Rapid7 (RPD) 10-K 28 Feb 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Feb. 22, 2019	Jun. 29, 2018
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Trading Symbol	RPD
Entity Registrant Name	RAPID7, INC.
Entity Central Index Key	1,560,327
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		47,992,369
Entity Public Float			$ 1,111,592,590

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 99,565	$ 51,562
Short-term investments	159,210	39,178
Accounts receivable, net of allowance for doubtful accounts of $1,624 and $1,478 at December 31, 2018 and 2017, respectively	74,935	73,661
Deferred contract acquisition and fulfillment costs, current portion	12,321	0
Prepaid expenses and other current assets	9,746	8,877
Total current assets	355,777	173,278
Long-term investments	44,892	1,102
Property and equipment, net	17,523	8,589
Goodwill	88,420	83,164
Intangible assets, net	23,955	16,640
Deferred contract acquisition and fulfillment costs, non-current portion	27,634	0
Other assets	1,168	1,363
Total assets	559,369	284,136
Current liabilities:
Accounts payable	7,048	2,240
Accrued expenses	37,376	29,728
Deferred revenue, current portion	189,855	155,811
Other current liabilities	707	1,706
Total current liabilities	234,986	189,485
Convertible senior notes, net	174,688	0
Deferred revenue, non-current portion	58,716	68,689
Other long-term liabilities	3,660	1,809
Total liabilities	472,050	259,983
Stockholders’ equity:
Preferred stock, $0.01 par value per share; 10,000,000 shares authorized at December 31, 2018 and 2017; 0 shares issued and outstanding at December 31, 2018 and 2017	0	0
Common stock, $0.01 par value per share; 100,000,000 shares authorized at December 31, 2018 and 2017; 48,087,257 and 44,540,544 shares issued at December 31, 2018 and 2017, respectively; 47,600,449 and 44,053,736 shares outstanding at December 31, 2018 and 2017, respectively	476	441
Treasury stock, at cost, 486,808 shares at December 31, 2018 and 2017	(4,764)	(4,764)
Additional paid-in-capital	556,223	463,428
Accumulated other comprehensive loss	(31)	(39)
Accumulated deficit	(464,585)	(434,913)
Total stockholders’ equity	87,319	24,153
Total liabilities and stockholders’ equity	$ 559,369	$ 284,136

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Allowance for doubtful accounts receivable	$ 1,624	$ 1,478
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	48,087,257	44,540,544
Common stock, shares outstanding	47,600,449	44,053,736
Treasury Stock, shares	486,808	486,808

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue:
Total revenue	$ 244,091	$ 200,940	$ 157,437
Cost of revenue:
Total cost of revenue	71,083	56,910	39,725
Total gross profit	173,008	144,030	117,712
Operating expenses:
Research and development	67,743	50,938	47,955
Sales and marketing	123,310	111,593	90,524
General and administrative	34,993	30,293	28,282
Total operating expenses	226,046	192,824	166,761
Loss from operations	(53,038)	(48,794)	(49,049)
Other income (expense), net:
Interest income	3,229	862	342
Interest expense	(4,934)	(87)	(211)
Other income (expense), net	(336)	313	(109)
Loss before income taxes	(55,079)	(47,706)	(49,027)
Provision for (benefit from) income taxes	466	(2,236)	(27)
Net loss	$ (55,545)	$ (45,470)	$ (49,000)
Net loss per share, basic and diluted (in dollars per share)	$ (1.20)	$ (1.06)	$ (1.19)
Weighted-average common shares outstanding, basic and diluted (in shares)	46,456,825	42,952,950	41,248,473
Product [Member]
Revenue:
Total revenue	$ 168,571	$ 116,748	$ 89,404
Cost of revenue:
Total cost of revenue	39,810	25,583	12,447
Maintenance [Member]
Revenue:
Total revenue	42,223	46,268	37,403
Cost of revenue:
Total cost of revenue	7,678	7,491	7,105
Professional Services [Member]
Revenue:
Total revenue	33,297	37,924	30,630
Cost of revenue:
Total cost of revenue	$ 23,595	$ 23,836	$ 20,173

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net loss	$ (55,545)	$ (45,470)	$ (49,000)
Other comprehensive loss:
Change in fair value of investments	8	(23)	(19)
Adjustment for net losses realized and included in net loss	0	3	0
Total change in unrealized losses on investments	8	(20)	(19)
Comprehensive loss	$ (55,537)	$ (45,490)	$ (49,019)

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS’ EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income [Member]	Accumulated Deficit [Member]
Beginning Balance (in shares) at Dec. 31, 2015		41,540	402
Beginning Balance at Dec. 31, 2015	$ 68,075	$ 415	$ (3,526)	$ 411,524	$ 0	$ (340,338)
Stock-based compensation expense	17,316			17,316
Issuance of common stock under ESPP (in shares)		346
Issuance of common stock under ESPP	3,724	$ 4		3,720
Vesting of restricted stock units (in shares)		91
Vesting of restricted stock units	0	$ 1		(1)
Forfeiture of restricted stock awards (in shares)		(27)
Forfeiture of restricted stock awards	0
Shares withheld for employee taxes (in shares)		(74)	(62)
Shares withheld for employee taxes	(1,026)	$ (1)	$ (865)	(160)
Excess tax benefit from stock-based compensation	87			87
Issuance of common stock upon exercise of stock options (in shares)		679
Issuance of common stock upon exercise of stock options	2,881	$ 7		2,874
Net unrealized gain on investments	(19)				(19)
Net loss	(49,000)					(49,000)
Ending Balance (in shares) at Dec. 31, 2016		42,555	464
Ending Balance at Dec. 31, 2016	42,038	$ 426	$ (4,391)	435,360	(19)	(389,338)
Stock-based compensation expense	19,541			19,541
Issuance of common stock under ESPP (in shares)		247
Issuance of common stock under ESPP	2,914	$ 3		2,911
Vesting of restricted stock units (in shares)		436
Vesting of restricted stock units	0	$ 4		(4)
Forfeiture of restricted stock awards (in shares)		(21)
Forfeiture of restricted stock awards	0
Shares withheld for employee taxes (in shares)		(50)	(23)
Shares withheld for employee taxes	(698)	$ (1)	$ (373)	(324)
Issuance of common stock upon exercise of stock options (in shares)		887
Issuance of common stock upon exercise of stock options	5,848	$ 9		5,839
Net unrealized gain on investments	(20)				(20)
Net loss	(45,470)					(45,470)
Ending Balance (in shares) at Dec. 31, 2017		44,054	487
Ending Balance at Dec. 31, 2017	24,153	$ 441	$ (4,764)	463,428	(39)	(434,913)
Stock-based compensation expense	27,593			27,593
Equity component of convertible senior notes, net	52,194			52,194
Purchase of capped calls related to convertible senior notes	(26,910)			(26,910)
Issuance of common stock related to secondary offering (in shares)		1,500
Issuance of common stock related to secondary offering	30,907	$ 15		30,892
Issuance of common stock under ESPP (in shares)		219
Issuance of common stock under ESPP	3,637	$ 2		3,635
Vesting of restricted stock units (in shares)		973
Vesting of restricted stock units	0	$ 10		(10)
Forfeiture of restricted stock awards (in shares)		(3)
Forfeiture of restricted stock awards	0
Shares withheld for employee taxes (in shares)		(88)
Shares withheld for employee taxes	(2,197)	$ (1)		(2,196)
Issuance of common stock upon exercise of stock options (in shares)		945
Issuance of common stock upon exercise of stock options	7,606	$ 9		7,597
Net unrealized gain on investments	8				8
Net loss	(55,545)					(55,545)
Ending Balance (in shares) at Dec. 31, 2018		47,600	487
Ending Balance at Dec. 31, 2018	$ 87,319	$ 476	$ (4,764)	$ 556,223	$ (31)	$ (464,585)

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net loss	$ (55,545,000)	$ (45,470,000)	$ (49,000,000)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	11,097,000	7,628,000	6,725,000
Amortization of debt discount and issuance costs	3,831,000	0	0
Stock-based compensation expense	27,593,000	19,541,000	17,316,000
Provision for doubtful accounts	740,000	905,000	931,000
Deferred income taxes	(69,000)	(2,860,000)	75,000
Foreign currency re-measurement (gain) loss	757,000	(364,000)	58,000
Other non-cash items	(506,000)	209,000	222,000
Changes in assets and liabilities:
Accounts receivable	(1,685,000)	(25,217,000)	(6,195,000)
Deferred contract acquisition and fulfillment costs	(12,790,000)	0	0
Prepaid expenses and other assets	(287,000)	(74,000)	(3,523,000)
Accounts payable	3,675,000	(2,257,000)	1,619,000
Accrued expenses	6,018,000	6,758,000	1,578,000
Deferred revenue	22,870,000	55,437,000	38,748,000
Other liabilities	367,000	(950,000)	558,000
Net cash provided by operating activities	6,066,000	13,286,000	9,112,000
Cash flows from investing activities:
Business acquisitions, net of cash acquired	(14,460,000)	(14,717,000)	0
Purchases of property and equipment	(12,813,000)	(4,824,000)	(4,499,000)
Capitalization of internal-use software	(3,265,000)	(1,162,000)	0
Purchases of investments	(233,421,000)	(35,190,000)	(38,976,000)
Sales and maturities of investments	70,226,000	33,672,000	0
Net cash used in investing activities	(193,733,000)	(22,221,000)	(43,475,000)
Cash flows from financing activities:
Proceeds from issuance of convertible senior notes, net of issuance costs of $6,879	223,121,000	0	0
Purchase of capped calls related to convertible senior notes	(26,910,000)	0	0
Proceeds from secondary public offering, net of offering costs of $608	30,907,000	0	0
Deferred business acquisition payment	0	(796,000)	(1,392,000)
Payments of capital lease obligations	0	0	(68,000)
Taxes paid related to net share settlement of equity awards	(2,197,000)	(698,000)	(4,114,000)
Excess tax benefit from stock-based compensation	0	0	87,000
Proceeds from employee stock purchase plan	3,637,000	2,914,000	3,724,000
Proceeds from stock option exercises	7,606,000	5,848,000	2,924,000
Net cash provided by financing activities	236,164,000	7,268,000	1,161,000
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(694,000)	281,000	(203,000)
Net increase (decrease) in cash, cash equivalents and restricted cash	47,803,000	(1,386,000)	(33,405,000)
Cash, cash equivalents and restricted cash, beginning of period	51,762,000	53,148,000	86,553,000
Cash, cash equivalents and restricted cash, end of period	99,565,000	51,762,000	53,148,000
Supplemental cash flow information:
Cash paid for income taxes	188,000	801,000	556,000
Cash paid for interest	0	0	5,000
Reconciliation of cash, cash equivalents and restricted cash:
Total cash, cash equivalents and restricted cash	$ 51,762,000	$ 53,148,000	$ 86,553,000

CONSOLIDATED STATEMENTS OF CA_2

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)
Statement of Cash Flows [Abstract]
Payments of debt issuance costs	$ 6,879
Offering costs	$ 608

Nature of the Business

Nature of the Business	12 Months Ended
	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of the Business	Nature of the Business Rapid7, Inc. and subsidiaries (“we,” “us” or “our”) is advancing security with visibility, analytics, and automation delivered through our Insight cloud. Our solutions simplify the complex, allowing security teams to work more effectively with IT and development to reduce vulnerabilities, monitor for malicious behavior, investigate and shut down attacks, and automate routine tasks.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies (a) Basis of Presentation and Consolidation The accompanying consolidated financial statements include our results of operations and those of our wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated in consolidation. The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP). (b) Use of Estimates The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates, judgments and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Significant items subject to such estimates and assumptions include the determination of the estimated economic life of perpetual licenses for revenue recognition, the determination of standalone selling prices in revenue transactions with multiple performance obligations, the estimated period of benefit for deferred contract acquisition and fulfillment costs, the valuation of allowance for doubtful accounts, the valuation of stock-based compensation and the valuation of intangible assets acquired in a business combination. We base our estimates on historical experience and on various other assumptions that we believe are reasonable. Actual results could differ from those estimates. (c) Revenue Recognition We generate products revenue from the sale of (1) cloud-based subscriptions for our InsightIDR, InsightVM, InsightAppSec and InsightConnect products, (2) managed services offerings which utilize our products and (3) term or perpetual software licenses for our Nexpose, Metasploit, AppSpider and Komand products, and associated content subscriptions for our Nexpose and Metasploit products. We also generate appliance revenue that is included in our products revenue and is associated with hardware sold with our Nexpose product to certain customers. We generate maintenance and support revenue associated with customers’ purchases of our software licenses for Nexpose, Metasploit, AppSpider and Komand. We generate professional service revenue from the sale of our deployment and training services related to our solutions, incident response services and security advisory services. Our deployment services educate and assist our customers on the best use and best practices to deploy our solutions. We adopted Financial Accounting Standards Board (FASB) Accounting Standards Update (ASU) 2014-09, Revenue from Contracts with Customers (Topic 606) (ASC 606) on January 1, 2018 using the modified retrospective method. Under this method of adoption, we recognized the cumulative effect of initially applying the new revenue standard as an adjustment to the opening balance of accumulated deficit. Comparative prior periods were not adjusted. In accordance with ASC 606, revenue is recognized when a customer obtains control of promised products or services. The amount of revenue recognized reflects the consideration that we expect to be entitled to receive in exchange for these products or services. To achieve the core principle of this standard, we apply the following five steps: 1) Identify the contract with a customer We consider the terms and conditions of the contracts and our customary business practices in identifying our contracts under ASC 606. We determine we have a contract with a customer when the contract is approved, we can identify each party’s rights regarding the services to be transferred, we can identify the payment terms for the services, and we have determined the customer has the ability and intent to pay and the contract has commercial substance. We apply judgment in determining the customer’s ability and intent to pay, which is based on a variety of factors, including the customer’s historical payment experience or, in the case of a new customer, credit and financial information pertaining to the customer. 2) Identify the performance obligations in the contract Performance obligations promised in a contract are identified based on the products and services that will be transferred to the customer that are both capable of being distinct, whereby the customer can benefit from the product or service either on its own or together with other resources that are readily available from third parties or from us, and are distinct in the context of the contract, whereby the transfer of the products or services is separately identifiable from other promises in the contract. 3) Determine the transaction price The transaction price is determined based on the consideration to which we expect to be entitled in exchange for transferring products or services to the customer. Variable consideration is included in the transaction price if, in our judgment, it is probable that no significant future reversal of cumulative revenue under the contract will occur. In instances where the timing of revenue recognition differs from the timing of invoicing, we have determined our contracts generally do not include a significant financing component. The primary purpose of our invoicing terms is to provide customers with simplified and predictable ways of purchasing our products and services, not to receive financing from our customers or to provide customers with financing. Examples include invoicing at the beginning of a subscription term with revenue recognized ratably over the contract period. 4) Allocate the transaction price to performance obligations in the contract If the contract contains a single performance obligation, the entire transaction price is allocated to the single performance obligation. Contracts that contain multiple performance obligations require an allocation of the transaction price to each performance obligation based on a relative standalone selling price (“SSP”). 5) Recognize revenue when or as we satisfy a performance obligation Revenue is recognized at the time the related performance obligation is satisfied by transferring the promised product or service to a customer. Revenue is recognized when control of the products or services are transferred to our customers, in an amount that reflects the consideration that we expect to receive in exchange for those products or services. The following table summarizes revenue from contracts with customers for the year ended December 31, 2018 : Year Ended (in thousands) Subscription revenue $ 137,442 Term and perpetual software licenses 28,200 Maintenance and support 42,223 Professional services 33,297 Other 2,929 Total revenue $ 244,091 The following table summarizes the revenue by region based on the shipping address of customers who have contracted to use our product or service for the year ended December 31, 2018 : Year Ended (in thousands) United States $ 199,852 All other 44,239 Total revenue $ 244,091 Subscription Revenue Subscription revenue consists of revenue from our cloud-based subscription, managed services offerings and content subscriptions associated with our software licenses. • We generate cloud-based subscription revenue primarily from sales of subscriptions to access our cloud platform, together with related support services to our customers. These arrangements do not provide the customer with the right to take possession of our software operating on our cloud platform at any time. Instead, customers are granted continuous access to our cloud platform over the contractual period. Revenue is recognized over time on a ratable basis over the contract term beginning on the date that our service is made available to the customer. Our cloud-based subscription contracts generally have a term of 1 year which is billed in advance and non-cancellable. • Managed services offerings consist of fees generated when we operate our software and provide our capabilities on behalf of our customers. Revenue is recognized on a ratable basis over the contract term beginning on the date that our service is made available to the customer. Our managed services offerings generally have a term of 1 year which is billed in advance and non-cancellable. • Revenue related to our content subscriptions associated with our software licenses is recognized ratably over the contractual period. • Some of our customers have the option to purchase additional subscription and support services at a stated price. These options generally do not provide a material right as they are priced at our SSP. Certain subscription contracts contain service level commitments, which entitle our customers to receive service credits and, in certain cases, refunds, if our services do not meet certain levels. These service credits and refunds represent variable consideration. We have historically not experienced any significant incidents affecting the defined levels of reliability and performance as required by our subscription contracts and accordingly, no estimated refunds have been considered in the allocation of the transaction price. Term and Perpetual Software Licenses For our perpetual software licenses where the utility to the customer is dependent on the continued delivery of content subscriptions, the content subscription renewal options result in a material right with respect to the perpetual software license. As a result, the revenue attributable to the perpetual software license is recognized ratably over the customer’s estimated economic life of five years , which represents a longer period of time in comparison to the initial contractual period of maintenance and support. The estimated economic life of five years represents the period which the customer is expected to benefit from the material right. We estimated this period of benefit by taking into consideration several factors, including the terms and conditions of our customer contracts and renewals and the expected useful life of our technology. For our term software licenses where the utility to the customer is dependent on the continued delivery of content subscriptions, we recognize the license revenue over the contractual term of the arrangement as a material right does not exist. For our term and perpetual software licenses which are not dependent on the continued delivery of content subscriptions, the license is considered distinct from the maintenance and support, and we therefore recognize revenue attributable to the license at the time of delivery. Maintenance and Support Maintenance and support services are sold with our perpetual and term software licenses. As maintenance and support services are distinct from the perpetual and term software license, revenue attributable to maintenance and support services is recognized ratably over the contractual period. Professional Services All of our professional services are considered distinct performance obligations when sold stand alone or with other products. These contracts generally have terms of one year or less. For the majority of these contracts, revenue is recognized over time based upon the proportion of work performed to date. Other Other revenue primarily includes revenue from delivery of appliances and other miscellaneous revenue. Contracts with Multiple Performance Obligations The majority of our contracts with customers contain multiple performance obligations. For these contracts, we account for individual performance obligations separately if they are considered distinct. The transaction price is allocated to the separate performance obligations on a relative SSP basis. We determine SSP based on our overall pricing objectives, taking into consideration market conditions and other factors, including the geographic locations of our customers and selling method (i.e., partner or direct). Contract Balances Contract liabilities consist of deferred revenue and include payments received in advance of performance under the contract. Such amounts are recognized as revenue over the contractual period consistent with the above methodology. For the year ended December 31, 2018 , we recognized revenue of $135.6 million that was included in the corresponding contract liability balance at the beginning of the period presented. Deferred revenue that will be realized during the succeeding 12-month period is recorded as current, and the remaining deferred revenue is recorded as non-current. We receive payments from customers based upon contractual billing schedules. Accounts receivable are recorded when the right to consideration becomes unconditional. Contract assets, or unbilled receivables, include amounts related to our contractual right to consideration for both completed and partially completed performance obligations that may not have been invoiced. As of January 1, 2018 and December 31, 2018 , contract assets of $0.3 million and $0.8 million , respectively, are included in prepaid expenses and other current assets in our consolidated balance sheet. Transaction Price Allocated to the Remaining Performance Obligations The following table includes estimated revenue expected to be recognized in the future related to performance obligations that are unsatisfied or partially unsatisfied as of December 31, 2018 . The estimated revenues do not include unexercised contract renewals. 2019 2020 2021 and thereafter (in thousands) Subscription revenue $ 129,539 $ 37,471 $ 980 Term and perpetual software licenses 22,880 20,776 4,043 Maintenance and support 26,966 6,536 110 The amounts presented in the table above primarily consist of fixed fees which are typically recognized ratably as the performance obligation is satisfied. As of December 31, 2018 , the estimated revenue expected to be recognized in the future related to performance obligations that are unsatisfied or partially unsatisfied associated with professional services was $12.0 million . We will recognize this revenue as the professional services are completed, which is expected to occur within the next 12 months or less. Transition Disclosures For periods prior to January 1, 2018, we recognized revenue in accordance with FASB ASC Topic 605, Revenue Recognition (ASC 605). In accordance with the modified retrospective method transition requirements, we will present the financial statement line items impacted and adjusted to compare to presentation under ASC 605 for each of the interim and annual periods during the first year of our adoption of ASC 606. The following tables summarize the impact as of and for the year ended December 31, 2018 : As of December 31, 2018 Balance Sheet As Reported under ASC 606 Proforma as if ASC 605 was in effect (in thousands) Cash and cash equivalents $ 99,565 $ 99,565 Short-term investments 159,210 159,210 Accounts receivable, net 74,935 74,935 Deferred contract acquisition and fulfillment costs, current portion 12,321 — Prepaid expenses and other current assets 9,746 9,281 Long-term investments 44,892 44,892 Property and equipment, net 17,523 17,523 Goodwill 88,420 88,420 Intangible assets, net 23,955 23,955 Deferred contract acquisition and fulfillment costs, non-current portion 27,634 — Other assets 1,168 1,168 Total assets $ 559,369 $ 518,949 Accounts payable 7,048 7,048 Accrued expenses 37,376 37,376 Deferred revenue, current portion 189,855 193,763 Other current liabilities 707 707 Convertible senior notes, net 174,688 174,688 Deferred revenue, non-current portion 58,716 41,658 Other long-term liabilities 3,660 2,912 Total liabilities 472,050 458,152 Common stock 476 476 Treasury stock (4,764 ) (4,764 ) Additional paid-in-capital 556,223 556,223 Accumulated other comprehensive loss (31 ) (31 ) Accumulated deficit (464,585 ) (491,107 ) Total stockholders’ equity 87,319 60,797 Total liabilities and stockholders’ equity $ 559,369 $ 518,949 Total reported assets were $40.4 million greater than the proforma balance sheet, which assumes the previous guidance remained in effect as of December 31, 2018 , largely due to deferred contract acquisition and fulfillment costs of $40.0 million . Total reported liabilities were $13.9 million greater than the proforma balance sheet primarily due to changes in deferred revenue and deferred tax liabilities. Year Ended December 31, 2018 Statement of Operations As Reported under ASC 606 Proforma as if ASC 605 was in effect (in thousands, except share and per share data) Revenue: Products $ 168,571 175,146 Maintenance and support 42,223 45,767 Professional services 33,297 35,010 Total revenue 244,091 255,923 Cost of revenue: Products 39,810 39,761 Maintenance and support 7,678 7,678 Professional services 23,595 23,577 Total cost of revenue 71,083 71,016 Total gross profit 173,008 184,907 Operating expenses: Research and development 67,743 67,743 Sales and marketing 123,310 136,167 General and administrative 34,993 34,993 Total operating expenses 226,046 238,903 Loss from operations (53,038 ) (53,996 ) Other income (expense), net: Interest income 3,229 3,229 Interest expense (4,934 ) (4,934 ) Other income (expense), net (336 ) (336 ) Loss before income taxes (55,079 ) (56,037 ) Provision for income taxes 466 157 Net loss $ (55,545 ) $ (56,194 ) Net loss per share, basic and diluted $ (1.20 ) $ (1.21 ) Weighted-average common shares outstanding, basic and diluted 46,456,825 46,456,825 The following summarizes the significant changes on the consolidated statement of operations for the year ended December 31, 2018 as a result of the adoption of ASC 606 on January 1, 2018 compared to if we had continued to recognize revenue under ASC 605: • Products revenue decreased $6.6 million for the year ended December 31, 2018 under ASC 606 primarily due to perpetual licenses revenue which are dependent on the continued delivery of content subscriptions and the change in the allocation of contract consideration to the relative fair value method under ASC 606 from the residual method under ASC 605. As a result of the allocation change, more contract consideration is allocated to license revenue under ASC 606. Given the utility of certain of our perpetual license products are dependent on the continued delivery of content subscriptions, the content subscription renewal option results in a material right with respect to the perpetual license. As a result, revenue allocated to the perpetual license is recognized ratably over the customer's estimated economic life of five years rather than over the contractual period of maintenance and support, typically one to three years . • Maintenance and support revenue decreased $3.5 million for the year ended December 31, 2018 under ASC 606 primarily due to the change in the allocation of contract consideration to the relative fair value method under ASC 606 from the residual method under ASC 605. As a result of the allocation change, more contract consideration is allocated to license revenue under ASC 606. • Professional services revenue decreased $1.7 million for the year ended December 31, 2018 under ASC 606 primarily due to the fact that our professional services are sold together with term or perpetual licenses. Under ASC 606, the professional services represent distinct performance obligations and therefore are recognized as services are performed. Under ASC 605, professional services sold together with term or perpetual licenses were recognized ratably over the contractual period of maintenance and support. • Sales and marketing expense decreased $12.9 million for the year ended December 31, 2018 under ASC 606 primarily due to the capitalization of commissions considered direct and incremental costs to obtain a contract partially offset by amortization of capitalized commissions. • Provision for income taxes increased $0.3 million for the year ended December 31, 2018 under ASC 606 due to additional deferred taxes for the temporary differences between the accounting and tax treatments of capitalized costs to obtain or fulfill a contract. Year Ended December 31, 2018 Statement of Cash Flows As Reported under ASC 606 Proforma as if ASC 605 was in effect (in thousands) Net loss $ (55,545 ) $ (56,194 ) Adjustments to reconcile net loss to net cash provided by operating activities 43,443 43,125 Changes in operating assets and liabilities: Accounts receivable (1,685 ) (1,685 ) Deferred contract acquisition and fulfillment costs (12,790 ) — Prepaid expenses and other assets (287 ) 146 Accounts payable 3,675 3,675 Accrued expenses 6,018 6,018 Deferred revenue 22,870 10,614 Other liabilities 367 367 Net cash provided by operating activities $ 6,066 $ 6,066 The adoption of ASC 606 resulted in offsetting changes in operating assets and liabilities and had no impact on net cash flow from operations. Legacy Revenue Accounting Policy For periods prior to January 1, 2018, revenue was recognized in accordance with ASC 605. Under ASC 605, revenue was recognized when all of the following were met: • Persuasive evidence of an arrangement existed . Binding agreements or purchase orders were generally evidence of an arrangement. • Delivery had occurred . Delivery occurred (1) upon delivery of the software license key or when the customer had access to the software product or (2) when we performed the services. • The sales price was fixed or determinable . Fees were considered fixed and determinable when the fees were contractually agreed upon with the customer. • Collectability was probable . Collectability was deemed probable based on review of a number of factors, including creditworthiness and customer payment history. If collectability was not probable, revenue was deferred until collection became probable, which was generally upon the receipt of payment. Substantially all of our software licenses were sold in multiple-element arrangements that included maintenance and support and content subscriptions, and in addition could include cloud-based subscriptions, professional services and/or managed services. All of these elements were considered to be software elements other than cloud-based subscriptions and managed services which were non-software elements. Non-software elements included in multiple-element arrangements consist of a single deliverable that had stand-alone value and represented a single unit of accounting. We determined that we did not have vendor-specific objective evidence, or VSOE, of the selling price for the elements comprising these multiple-element arrangements as our software licenses were generally not sold on a stand-alone basis and we purposefully employed variable pricing for our offerings in order to meet customer purchase requirements along the multiple price points of the demand curve. When all of the elements of a multiple-element arrangement were software elements, the revenue for software licenses and any other products and services that were sold along with the license was generally deferred on our balance sheet and recognized as revenue on our consolidated statements of operations ratably over the contractual period of the maintenance and support, typically one to three years, which was longer than the period over which the professional services were performed. Revenue recognition began upon delivery of the software license, assuming that all other criteria for revenue recognition had been met. When a multiple-element arrangement included both software elements and non-software elements, the total arrangement consideration was first allocated between the software elements and the non-software elements based on the selling price hierarchy, which included (1) VSOE, if available, (2) third-party evidence, or TPE, if VSOE was not available or (3) best estimate of selling price, or BESP, if neither VSOE nor TPE was available. We were not able to establish a selling price for any element using VSOE or TPE. We determined BESP by considering our overall pricing objectives and market conditions. Significant pricing practices taken into consideration included our discounting practices, the size and volume of our transactions, our price lists, our go-to-market strategy, historical standalone sales and contract prices. The determination of BESP was made in consultation with, and was approved by, our management. The portion of the consideration allocated to the non-software elements was recognized ratably over the service period of the non-software elements, assuming all other criteria for revenue recognition had been met. The portion of the consideration allocated to software elements was recognized as described above. With respect to our managed services and cloud-based subscription offerings sold on a stand-alone basis, we recognized revenue ratably over the term of the managed service agreement or subscription, assuming that the other criteria for revenue recognition were met. We recognized revenue from professional services sold on a stand-alone basis as those services were rendered. For purposes of disclosing revenue by class, we allocated the arrangement consideration for multiple-element software arrangements among the individual elements utilizing BESP, as we did not have VSOE or TPE of selling price for any of the elements. (d) Cash and Cash Equivalents We consider all highly liquid instruments with original maturities of three months or less at the date of purchase to be cash equivalents. Cash and cash equivalents are recorded at cost, which approximates fair value. As of December 31, 2018 and 2017 , $58.6 million and $0.1 million , respectively, of our cash equivalents were invested in money market funds, U.S. Government agencies and commercial paper. (e) Restricted Cash As of December 31, 2017 , we had $0.2 million of restricted cash recorded on our balance sheet in other non-current assets as collateral for a credit card program. This restricted cash was released during 2018, therefore as of December 31, 2018 , we had no restricted cash on our balance sheet. (f) Investments We classify our investments as available-for-sale and record these investments at fair value. We currently invest primarily in commercial paper, corporate bonds, agency bonds, U.S. Government agencies and asset-backed securities. Investments with an original maturity of greater than three months at the date of purchase and less than one year from the date of the balance sheet are classified as short-term and those with maturities of more than one year from the date of the balance sheet are classified as long-term in the consolidated balance sheet. Additionally, we do not invest in any securities with contractual maturities greater than 24 months. Unrealized gains and losses that are considered temporary are reported as a component of other comprehensive loss. Realized gains and losses are determined based on the specific identification method, and are reflected in our consolidated statements of operations. We regularly review our investment portfolio to identify and evaluate investments that have indicators of possible impairment. Factors considered in determining whether a loss is other-than-temporary include, but are not limited to: the length of time and extent a security’s fair value has been below its cost, the financial condition and near-term prospects of the investee, the credit quality of the security’s issuer, likelihood of recovery and our intent and ability to hold the security for a period of time sufficient to allow for any anticipated recovery in value. For our debt instruments, we also evaluate whether we have the intent to sell the security or it is more likely than not that we will be required to sell the security before recovery of its cost basis. (g) Accounts Receivable and Allowance for Doubtful Accounts Accounts receivable are recorded at the invoiced amount, net of allowances for doubtful accounts. Management regularly reviews the adequacy of the allowance for doubtful accounts by considering the age of outstanding invoices, the customer’s expected ability to pay and the collection history, when applicable, to determine whether an allowance is appropriate. Accounts receivable are charged against the allowance for doubtful accounts after all means of collection have been exhausted and the potential for recovery is considered remote. Additions to the allowance for doubtful accounts are recorded in general and administrative expense in the consolidated statement of operations. We do not have any off-balance sheet credit exposure related to our customers. The following table displays the changes in our allowance for doubtful accounts: Amount (in thousands) Balance at December 31, 2015 $ 730 Additions, net of recoveries 931 Less write-offs (600 ) Balance at December 31, 2016 1,061 Additions, net of recoveries 905 Less write-offs (488 ) Balance at December 31, 2017 1,478 Additions, net of recoveries 740 Less write-offs (594 ) Balance at December 31, 2018 $ 1,624 (h) Concentration of Credit Risk Financial instruments that potentially expose us to concentrations of credit risk consist primarily of cash and cash equivalents, accounts receivable and short-term and long-term investments. As of December 31, 2018 and 2017 , $58.6 million and $0.1 million , respectively, of our cash equivalents were invested in money market funds, U.S. Government agencies and commercial paper. Deposits held with banks may exceed the amount of insurance provided on such deposits. We have not experienced any losses in such accounts and believe that we are not exposed to any significant risk. We provide credit to customers in the normal course of business. Collateral is not required for accounts receivable, but ongoing credit evaluations of customers’ financial condition are performed. We maintain reserves for potential credit losses. No single customer, including channel partners, accounted for 10% or more of our total revenues in 2018 , 2017 or 2016 or accounts receivable as of December 31, 2018 or 2017 . Our short-term and long-term investments primarily consist of commercial paper, corporate bonds, agency bonds, U.S. Government agencies and asset-backed securities. All of our investments are highly-rated by credit rating agencies and are issued by organizations with reputable credit, and therefore bear minimal credit risk. (i) Property and Equipment Property and equipment are recorded at cost and depreciated over their estimated useful lives using the straight-line method. The following table presents the useful lives of our property and equipment: Useful Lives Computer equipment and software 3 years Furniture and fixtures 5 - 7 years Leasehold improvements Shorter of the useful life of the asset or the lease term Upon sale, the cost of assets disposed and the related accumulated depreciation are removed from the accounts and any resulting gain or loss is recognized in the consolidated statements of operations. Repairs and maintenance costs are expensed as incurred. (j) Software Development Costs Software development costs associated with the development of products for sale are recorded to research and development expense until technological feasibility has been established for the product. Once technological feasibility is established, all software costs are capitalized until the product is available for release to customers. To date, the software development costs have not been capitalized as we believe our current software development process is essentially completed concurrently with the establishment of technological feasibility. As such, these costs are expensed as incurred and recognized in research and development expenses in our consolidated statements of operations. With respect to software developed for internal use, we capitalize qualifying internal costs, such as payroll and benefits of those employees directly associated with the development of the software, and other qualifying consulting costs. Costs incurred during the preliminary planning and evaluation and post implementation stages of the project are expensed as incurred. Costs incurred during the application development stage of the project are capitalized. We capitalized $3.3 million , $1.2 million and $0 of costs related to software developed for internal use in the years ended December 31, 2018, 2017 and 2016, respectively. Total unamortized costs relating to software developed for internal use was $3.4 million and $1.1 million as of December 31, 2018 and 2017 , respectively. These costs are included in long-term assets as part of intangible assets, net in our consolidated balance sheet. (k) Long-Lived Assets We evaluate our long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying value of these assets may not be recoverable. When such events or changes in circumstances occur, recoverability of these assets is measured by a comparison of the carryin

Business Combinations

Business Combinations	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Business Combinations	Business Combinations tCell.io, Inc. On October 15, 2018, we acquired tCell.io, Inc. (tCell) for total cash consideration of $15.4 million . We expensed the related acquisition costs of $0.1 million in general and administrative expense. The following table summarizes the cash consideration paid for tCell and the preliminary allocation of purchase price to the estimated fair value of the assets acquired and liabilities assumed at the acquisition date (in thousands): Cash consideration $ 15,414 Recognized amount of identifiable assets acquired and liabilities assumed: Cash and cash equivalents 1,089 Other net working capital (91 ) Intangible asset 9,160 Total identifiable net assets assumed 10,158 Goodwill 5,256 Total purchase price allocation $ 15,414 The fair value of the identifiable intangible asset was based on a valuation using a cost approach. The estimated fair value and useful life of the identifiable intangible asset was as follows: Amount Weighted Average Amortization Life (years) (in thousands) Developed technology $ 9,160 5 The excess of the purchase price over the tangible assets acquired, identifiable intangible asset acquired and assumed liabilities was recorded as goodwill. We believe that the amount of goodwill reflects the expected synergistic benefits of being able to leverage the integration of our existing product offerings with the products and technology acquired in connection with our acquisition of tCell and to successfully market and sell these new products to our customer base. The goodwill was allocated to our one reporting unit. The acquired goodwill will not be deductible for tax purposes. These preliminary amounts are subject to subsequent adjustment as we obtain additional information to finalize certain components of working capital. Following the acquisition, certain retained employees and non-employee contractors of tCell received an aggregate of 112,924 RSUs which will vest over a maximum of three years . The vesting of the RSUs are subject to the employee's continued service with us. Accordingly, compensation expense associated with the RSUs will be expensed as incurred in our post-acquisition financial statements. Proforma results of operations have not been included, as the acquisition of tCell was not material to our results of operations for any periods presented. Komand, Inc. On July 12, 2017, we acquired 100% of the outstanding equity of Komand, Inc. (Komand) for total cash consideration of $14.7 million , net of cash acquired of $0.1 million . We expensed the related acquisition costs of $0.2 million in general and administrative expense. The assets acquired and liabilities assumed were recorded at their estimated fair values as of the acquisition date. The excess of the purchase price over the assets acquired and liabilities assumed was recorded as goodwill. The fair value of goodwill and intangible assets were $8.1 million and $9.4 million , respectively. The goodwill was allocated to our one reporting unit. The acquired goodwill and intangible asset were not deductible for tax purposes. Accordingly, a $2.6 million deferred tax benefit was recorded resulting from a partial release of our valuation allowance to account for the creation of a deferred tax liability for the developed technology intangible asset acquired which was not deductible for tax purposes. Following the acquisition, certain retained employees of Komand (1) received an aggregate of 295,600 RSUs which will vest over four years and (2) shall be eligible for an aggregate of up to $5.0 million of incentive payments contingent on achievement of certain milestones within four years of the acquisition date. The vesting of the RSUs and eligibility to receive the incentive payments are each subject to the employee's continued service with us. Accordingly, compensation expense associated with the RSUs and incentive payments are expensed as incurred in our post-acquisition financial statements.

Fair Value Measurements and Inv

Fair Value Measurements and Investments	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements and Investments	Fair Value Measurements and Investments We measure certain financial assets and liabilities at fair value. Fair value is determined based upon the exit price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants, as determined by either the principal market or the most advantageous market. Inputs used in the valuation techniques to derive fair values are classified based on a three-level hierarchy, as follows: • Level 1 : Observable inputs that reflect quoted prices (unadjusted) for identical assets or liabilities in active markets. • Level 2 : Observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities; quoted prices in markets with insufficient volume or infrequent transactions (less active markets); or model-derived valuations in which all significant inputs are observable or can be derived principally from or corroborated by observable market data for substantially the full term of the assets or liabilities. • Level 3 : Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the asset or liability. We consider an active market to be one in which transactions for the asset or liability occur with sufficient frequency and volume to provide pricing information on an ongoing basis, and consider an inactive market to be one in which there are infrequent or few transactions for the asset or liability, the prices are not current, or price quotations vary substantially either over time or among market makers. The following table presents our financial assets measured and recorded at fair value on a recurring basis using the above input categories: As of December 31, 2018 Level 1 Level 2 Level 3 Total (in thousands) Description: Assets: Money market funds $ 55,646 $ — $ — $ 55,646 U.S. Government agencies 74,481 — — 74,481 Commercial paper — 57,554 — 57,554 Corporate bonds — 48,495 — 48,495 Agency bonds 19,087 19,087 Asset-backed securities — 7,483 — 7,483 Total assets $ 130,127 $ 132,619 $ — $ 262,746 As of December 31, 2017 Level 1 Level 2 Level 3 Total (in thousands) Description: Assets: Money market funds $ 95 $ — $ — $ 95 U.S. Government agencies 11,869 — — 11,869 Commercial paper — 12,942 — 12,942 Corporate bonds — 12,964 — 12,964 Asset-backed securities — 2,505 — 2,505 Total assets $ 11,964 $ 28,411 $ — $ 40,375 As of December 31, 2018 , the fair value of our 1.25% convertible senior notes due 2023 (Notes), as further described in Note 7, Convertible Senior Notes and Capped Calls , was $233.0 million based upon quoted market prices. We consider the fair value of the Notes to be a Level 2 measurement due to limited trading activity of the Notes. We had no financial liabilities measured and recorded at fair value on a recurring basis as of December 31, 2018 and 2017 . Our investments, which are all classified as available-for-sale, consisted of the following: As of December 31, 2018 Amortized Gross Gross Fair Value (in thousands) Description: U.S. Government agencies $ 71,480 $ 20 $ (17 ) $ 71,483 Commercial paper 57,554 — — 57,554 Corporate bonds 48,532 15 (52 ) 48,495 Agency bonds 19,077 16 (6 ) 19,087 Asset-backed securities 7,490 — (7 ) 7,483 Total $ 204,133 $ 51 $ (82 ) $ 204,102 As of December 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) Description: U.S. Government agencies $ 11,880 $ — $ (11 ) $ 11,869 Commercial paper 12,942 — — 12,942 Corporate bonds 12,991 — (27 ) 12,964 Asset-backed securities 2,506 — (1 ) 2,505 Total $ 40,319 $ — $ (39 ) $ 40,280 As of December 31, 2018 and 2017 , our available-for-sale investments had maturities ranging from 3 months to 2 years . Our available-for-sale investments as of December 31, 2018 included $3.0 million of U.S. Government agencies investments which are classified as cash and cash equivalents as the original maturity was less than three months. For all of our investments for which the amortized cost basis was greater than the fair value at December 31, 2018 and 2017 , we have concluded that there is no plan to sell the security nor is it more likely than not that we would be required to sell the security before its anticipated recovery. In making the determination as to whether the unrealized loss is other-than-temporary, we considered the length of time and extent the investment has been in an unrealized loss position, the financial condition and near-term prospects of the issuers, the issuers’ credit rating and the time to maturity.

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Property and Equipment	Property and Equipment Property and equipment are recorded at cost and consist of the following: As of December 31, 2018 2017 (in thousands) Computer equipment and software $ 18,724 $ 16,205 Furniture and fixtures 5,580 4,034 Leasehold improvements (1) 19,437 9,079 Total 43,741 29,318 Less accumulated depreciation (26,218 ) (20,729 ) Property and equipment, net $ 17,523 $ 8,589 (1) As of December 31, 2018, leasehold improvements included $4.0 million of construction-in progress related to our new Boston, Massachusetts corporate headquarters facility. We recorded depreciation expense of $6.5 million , $4.8 million and $4.3 million in 2018 , 2017 and 2016 , respectively.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Goodwill and Intangible Assets Goodwill was $88.4 million and $83.2 million as of December 31, 2018 and 2017 , respectively. There were no goodwill impairment charges in 2018 , 2017 or 2016 . The following table displays the changes in the gross carrying amount of goodwill: Amount (in thousands) Balance at December 31, 2016 $ 75,110 Komand acquisition 8,054 Balance at December 31, 2017 $ 83,164 tCell acquisition 5,256 Balance at December 31, 2018 $ 88,420 The following table presents details of our intangible assets which include acquired identifiable intangible assets and capitalized internal-use software costs: As of December 31, 2018 As of December 31, 2017 Weighted- Gross Carrying Accumulated Net Book Value Gross Carrying Accumulated Net Book Value (in thousands) Intangible assets subject to amortization: Developed technology 5.5 $ 29,771 $ (9,741 ) $ 20,030 $ 20,611 $ (5,756 ) $ 14,855 Customer relationships 6.7 1,000 (504 ) 496 1,000 (351 ) 649 Trade names 6.1 519 (516 ) 3 519 (510 ) 9 Non-compete agreements 2.0 40 (40 ) — 40 (40 ) — Total acquired intangible assets 31,330 (10,801 ) 20,529 22,170 (6,657 ) 15,513 Internal-use software 3,786 (360 ) 3,426 1,162 (35 ) 1,127 Total intangible assets $ 35,116 $ (11,161 ) $ 23,955 $ 23,332 $ (6,692 ) $ 16,640 Intangible assets are expensed on a straight-line basis over the useful life of the asset. We recorded amortization expense of $4.6 million , $2.8 million and $2.4 million in 2018 , 2017 and 2016 , respectively. Estimated future amortization expense of the acquired identifiable intangible assets and completed capitalized internal-use software costs as of December 31, 2018 is as follows (in thousands): 2019 $ 6,251 2020 6,193 2021 5,398 2022 2,927 2023 1,451 2024 and thereafter — Total $ 22,220 The table above excludes the impact of $1.7 million of capitalized internal-use software costs for projects that have not been completed as of December 31, 2018 , and therefore, we have not determined the useful life of the software, nor have all the costs associated with these projects been incurred.

Convertible Senior Notes and Ca

Convertible Senior Notes and Capped Calls	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Convertible Senior Notes and Capped Calls	Convertible Senior Notes and Capped Calls In August 2018, we issued $200.0 million aggregate principal amount of convertible senior notes due August 1, 2023 and an additional $30.0 million aggregate principal amount of such notes pursuant to the exercise in full of the over-allotment options of the initial purchasers (collectively, the Notes). The Notes are our senior unsecured obligations and bear interest at a fixed rate of 1.25% per annum, payable semi-annually in arrears on February 1 and August 1 of each year, commencing on February 1, 2019. The Notes will mature and are payable in full on August 1, 2023, unless earlier converted, redeemed or repurchased. The Notes do not contain any financial covenants. The total net proceeds from the Notes offering, after deducting initial purchase discounts and estimated debt issuance costs was $223.1 million . The Notes are governed by an indenture between the Company, as an issuer, and U.S. National Association, as trustee (the Indenture). Each $1,000 principal amount of the Notes is initially convertible into 24.0460 shares of our common stock, the Conversion Option, which is equivalent to an initial conversion price of approximately $41.59 per share, subject to adjustment upon the occurrence of specified events. The holders of the Notes may convert their notes at their option at any time prior to the close of business on the business day immediately preceding February 1, 2023, only under the following circumstances: (1) during any calendar quarter commencing after the calendar quarter ending on December 31, 2018 (and only during such calendar quarter), if the last reported sale price of our common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price of the Notes on each applicable trading day; (2) during the five business day period after any five consecutive trading day period (measurement period) in which the trading price (as defined in the Indenture) per $1,000 principal amount of the Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of our common stock and the conversion rate of the Notes on each such trading day; (3) if we call any or all of the Notes for redemption, at any time prior to the close of business on the scheduled trading day immediately preceding the redemption date; or (4) upon the occurrence of specified corporate events (as set forth in the Indenture). On or after February 1, 2023 until the close of business on the second scheduled trading day immediately preceding the maturity date, holders may convert their Notes at any time, regardless of the foregoing circumstances. Upon conversion, we will pay or deliver, as the case may be, cash, shares of our common stock or a combination of cash and shares of our common stock, at our election, in the manner and subject to the terms and conditions provided in the Indenture. We may not redeem the Notes prior to August 6, 2021. On or after August 6, 2021, we may redeem for cash all or any portion of the Notes, at our option, if the last reported sale price of our common stock has been at least 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period (including the last trading day of such period) ending on, and including the trading day immediately preceding, the date on which we provide the redemption notice at a redemption price equal to 100% principal amount of the Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date. If we undergo a fundamental change (as set forth in the Indenture) at any time prior to the maturity date, holders of the Notes, will have the right, at their option, to require us to repurchase for cash all or any portion of their Notes at a repurchase price equal to 100% of the principal amount of the Notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date. In addition, following certain corporate events that occur prior to the maturity date or following our issuance of a notice of redemption, in each case as described in the Indenture, we will increase the conversion rate for a holder of the Notes who elects to convert its Notes in connection with such a corporate event or during the related redemption period in certain circumstances. During the year ended December 31, 2018 , none of the conditions allowing holders of the Notes to convert their Notes had been met. The Notes are therefore not convertible as of December 31, 2018 and are classified as long-term debt. The foregoing description is qualified in its entirety by reference to the text of the Indenture and the Form of the Notes, which are incorporated by reference as Exhibits 4.4 and 4.5 to this Annual Report on Form 10-K. In accounting for the transaction, the Notes have been separated into liability and equity components. The initial carrying amount of the liability component was calculated by measuring the fair value of a similar debt instrument that does not have an associated convertible feature. The initial carrying amount of the equity component representing the Conversion Option was $53.8 million and was determined by deducting the fair value of the liability component from the par value of the Notes. The equity component was recorded as an increase to additional paid-in capital and is not remeasured as long as it continues to meet the conditions for equity classification. The excess of the principal amount of the Notes over the initial carrying amount of the liability component, the debt discount, is amortized to interest expense over the contractual term of the Notes at an effective interest rate of 7.36% . In accounting for the debt issuance costs of $6.9 million related to the Notes, we allocated the total amount incurred to the liability and equity components of the Notes based on their relative fair values. Issuance costs attributable to the liability component of $5.3 million are netted against the principal balance of the Notes and will be amortized to interest expense using the effective interest method over the contractual term of the Notes. Issuance costs attributable to the equity component of $1.6 million were netted with the equity component in additional paid-in capital. The net carrying amount of the liability component of the Notes was as follows: As of (in thousands) Principal $ 230,000 Unamortized debt discount (50,334 ) Unamortized issuance costs (4,978 ) Net carrying amount $ 174,688 The net carrying amount of the equity component was as follows: As of (in thousands) Debt discount for conversion option $ 53,820 Issuance costs (1,626 ) Net carrying amount $ 52,194 Interest expense related to the Notes was as follows: Year Ended December 31, 2018 (in thousands) Contractual interest expense $ 1,103 Amortization of debt discount 3,486 Amortization of issuance costs 345 Total interest expense $ 4,934 The future payments of the principal and contractual interest related to the Notes as of December 31, 2018 are as follows (in thousands): Principal Interest Total 2019 $ — $ 2,779 $ 2,779 2020 — 2,875 2,875 2021 — 2,875 2,875 2022 — 2,875 2,875 2023 230,000 2,875 232,875 Total $ 230,000 $ 14,279 $ 244,279 In connection with the offering of the Notes, we entered into privately negotiated capped call transactions with certain counterparties (Capped Calls). The Capped Calls each have an initial strike price of $41.59 per share, subject to certain adjustments, which correspond to the initial conversion price of the Notes. The Capped Calls have initial cap prices of $63.98 per share, subject to certain adjustments. The Capped Calls are expected to offset potential dilution to our common stock upon conversion of the Notes, with such offset subject to a cap based on the cap price. The Capped Calls cover, subject to anti-dilution adjustments, approximately 5.5 million shares of our common stock. For accounting purposes, the Capped Calls are separate transactions, and not part of the terms of the Notes. The Capped Calls are recorded in stockholders' equity and are not accounted for as derivatives. Accordingly, the cost of $26.9 million incurred in connection with the Capped Calls was recorded as a reduction to additional paid-in capital. The debt discount and the difference between the calculation of the book and tax allocation of debt issuance costs between the liability and equity components of the Notes, resulted in a difference between the carrying amount and tax basis of the Notes. This taxable temporary difference resulted in the recognition of a $13.0 million deferred tax liability which was recorded as a reduction to additional paid-in capital. The creation of the deferred tax liability represents a source of future taxable income which supports realization of a portion of our deferred tax assets. Therefore, we released $13.0 million of our valuation allowance which was recorded as an offsetting increase to additional paid-in capital. Accordingly, the net impact to additional paid-in capital as a result of the recognition of the deferred tax liability and the release of the valuation allowance was zero. The net impact to our stockholders' equity, included in additional paid-in capital, of the above components of the Notes was as follows (in thousands): Conversion option $ 53,820 Purchase of capped calls (26,910 ) Issuance costs (1,626 ) Total $ 25,284

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity (a) Common Stock On January 30, 2018, we completed a public offering of 5,950,000 shares of our common stock, of which 1,500,000 shares of common stock were sold by us and 4,450,000 shares of common stock were sold by certain existing stockholders, at an offering price of $22.00 per share, including 770,000 shares pursuant to the underwriters' option to purchase additional shares from the existing stockholders. Our net proceeds from the offering were $30.9 million , after deducting underwriting discounts and commissions and our offering expenses. We did not receive any of the proceeds from the sale of shares by the existing stockholders. (b) Treasury Stock In 2017 , we repurchased 22,754 shares of common stock for an aggregate amount of $0.4 million to settle employee withholding taxes upon the vesting of restricted stock awards.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock-Based Compensation ( a) General In connection with our IPO, our board of directors resolved not to make future grants under our 2011 Stock Option and Grant Plan (the 2011 Plan). The 2011 Plan will continue to govern outstanding awards granted thereunder. The 2011 Plan provided for the grant of qualified incentive stock options and nonqualified stock options or other awards such as RSAs to our employees, officers, directors and outside consultants. In July 2015, our board of directors adopted and our stockholders approved our 2015 Equity Incentive Plan (the 2015 Plan). We initially reserved 800,000 shares of our common stock for the issuance of awards under the 2015 Plan plus the number of shares of common stock reserved for issuance under the 2011 Plan at the time the 2015 Plan became effective. The 2015 Plan also provides that (i) any shares subject to awards granted under the 2011 Plan that would have otherwise returned to the 2011 Plan (such as upon the expiration or termination of a stock award prior to vesting) will be added to, and available for issuance under, the 2015 Plan and (ii) the number of shares reserved and available for issuance under the 2015 Plan automatically increases each January 1, beginning on January 1, 2016, by 4% of the outstanding number of shares of our common stock on the immediately preceding December 31 (known as the “evergreen” provision) or such lesser number of shares as determined by our board of directors. Additionally, on October 8, 2015, our board of directors amended, effective as of the acquisition of Logentries, the 2015 Plan to reserve an additional 1,500,000 shares of our common stock for issuance of inducement awards. In March 2018 , 2017 and 2016 , we increased the number of shares authorized to be issued under the 2015 Plan by 1,762,149 , 1,702,187 and 1,661,616 shares, respectively, which represents the amount automatically added pursuant to the annual evergreen provision contained therein. As of December 31, 2018 , the shares of common stock authorized to be issued under the 2015 Plan totaled 11,888,081 and there were 998,777 shares of common stock available for grant. We recognize stock-based compensation expense for all awards on a straight-line basis over the applicable vesting period, which is generally four years. Stock-based compensation expense for restricted stock, restricted stock units, stock options and issuances of common stock pursuant to our employee stock purchase plan was classified in the accompanying consolidated statements of operations as follows: Year Ended December 31, 2018 2017 2016 (in thousands) Stock-based compensation expense: Cost of revenue $ 1,692 $ 1,085 $ 610 Research and development 10,822 7,205 6,054 Sales and marketing 7,569 5,756 6,607 General and administrative 7,510 5,495 4,045 Total stock-based compensation expense $ 27,593 $ 19,541 $ 17,316 (b) Restricted Stock and Restricted Stock Units Restricted stock and restricted stock unit activity during 2018 , 2017 and 2016 was as follows: Restricted Stock Restricted Stock Units Shares Weighted- Shares Weighted- Unvested balance as of December 31, 2015 1,149,257 $ 19.34 — $ — Granted — — 919,397 13.37 Vested (538,896 ) 20.67 (91,020 ) 12.93 Forfeited (25,357 ) 20.96 (93,800 ) 12.97 Unvested balance as of December 31, 2016 585,004 18.05 734,577 13.47 Granted — — 1,938,860 14.97 Vested (358,214 ) 17.85 (435,573 ) 13.80 Forfeited (16,707 ) 23.01 (249,355 ) 14.22 Unvested balance as of December 31, 2017 210,083 18.00 1,988,509 14.77 Granted — — 2,099,394 25.19 Vested (187,706 ) 18.80 (973,443 ) 17.41 Forfeited (700 ) 23.01 (340,687 ) 18.96 Unvested balance as of December 31, 2018 21,677 $ 10.88 2,773,773 $ 21.21 As of December 31, 2018 , the unrecognized compensation cost related to shares of unvested restricted stock and restricted stock units expected to vest was $54.4 million . This unrecognized compensation will be recognized over an estimated weighted-average amortization period of 2.7 years. (c) Stock Options The following table summarizes information about stock option activity during the reporting periods: Shares Weighted Weighted Aggregate Outstanding as of December 31, 2015 4,246,525 $ 5.99 Granted 1,454,626 13.43 Options assumed from acquisition — — Exercised (650,185 ) 4.43 $ 6,409 Forfeited/cancelled (470,591 ) 9.65 Outstanding as of December 31, 2016 4,580,375 8.20 Granted 1,304,238 13.52 Exercised (887,062 ) 6.59 $ 9,665 Forfeited/cancelled (312,597 ) 12.79 Outstanding as of December 31, 2017 4,684,954 9.68 Granted 107,850 24.44 Exercised (944,658 ) 8.05 $ 19,982 Forfeited/cancelled (134,967 ) 15.20 Outstanding as of December 31, 2018 3,713,179 $ 10.32 6.20 $ 77,396 Vested and exercisable as of December 31, 2018 2,685,963 $ 8.76 5.55 $ 60,169 As of December 31, 2018 , the unrecognized compensation cost related to our unvested stock options expected to vest was $6.4 million . This unrecognized compensation will be recognized over an estimated weighted-average amortization period of 1.9 years. The total fair value of stock options vested in 2018 , 2017 and 2016 was $5.1 million , $5.9 million and $3.4 million , respectively. The weighted-average grant date fair value per share of stock options granted in 2018 , 2017 and 2016 was $11.86 , $6.72 and $6.38 per share, respectively. (d) Determining the Fair Value of Options We use the Black-Scholes option pricing model to estimate the fair value of stock option awards. The Black-Scholes option pricing model requires management to make a number of assumptions, including the expected life of the option, the volatility of the underlying stock, the risk-free interest rate and expected dividends. The assumptions used in our Black-Scholes option-pricing model represent management’s best estimates at the time of grant. These estimates involve a number of variables, uncertainties and assumptions and the application of management’s judgment, as they are inherently subjective. If any assumptions change, our stock-based compensation expense could be materially different in the future. Expected Term The expected term represents the period that our stock options are expected to be outstanding. We calculated the expected term using the simplified method based on the average of each option’s vesting term and the contractual period during which the option can be exercised, which is typically 10 years following the date of grant. Expected Volatility We determine the price volatility factor based on the historical volatilities of our publicly traded peer group as we do not have a significant trading history for our common stock. Industry peers consist of several public companies in the technology industry that are similar to us in size, stage of life cycle, and financial leverage. We used the same set of peer group companies in all the relevant valuation estimates. We intend to continue to consistently apply this process using the same or similar public companies until a sufficient amount of historical information regarding the volatility of our own common stock share price becomes available, or unless circumstances change such that the identified companies are no longer similar to us, in which case, more suitable companies whose share prices are publicly available would be utilized in the calculation. Risk-Free Interest Rate The risk-free interest rate was based on U.S. Treasury zero-coupon securities with maturities consistent with the estimated expected term. Expected Dividend Yield We have not paid dividends on our common stock nor do we expect to pay dividends in the foreseeable future. The following table reflects the range of assumptions for options granted during 2018 , 2017 and 2016 : Year Ended December 31, 2018 2017 2016 Expected term (in years) 6.1 5.5 - 6.1 5.5 – 6.3 Expected volatility 46 – 48% 48 – 52% 48 – 50% Risk-free interest rate 2.4 – 2.8% 1.8 – 2.2% 1.2 – 1.9% Expected dividend yield — — — Grant date fair value per share $ 10.55 – 13.11 $ 6.09 – 9.38 $ 5.53 – 8.35 (e) Employee Stock Purchase Plan On July 17, 2015, we filed a registration statement on Form S-8 with the Securities and Exchange Commission registering 800,000 shares of our common stock reserved under our 2015 Employee Stock Purchase Plan (ESPP). Under the ESPP, employees may set aside after-tax withholdings to purchase our common shares at a discounted price. In March 2018 , 2017 and 2016 , we increased the number of shares to be authorized under the ESPP by 440,537 , 425,547 and 415,404 shares, respectively, which represents the amount automatically added pursuant to the annual evergreen provision of the ESPP. As of December 31, 2018 , the shares of common stock authorized to be issued under the ESPP totaled 2,081,488 and there were 1,268,266 shares of common stock available for grant. Under the ESPP, employees may set aside up to 15% of their gross earnings, on an after-tax basis, to purchase our common shares at a discounted price, which is calculated at 85% of the lesser of: (i) the market value of our common stock at the beginning of each offering period and (ii) the market value of our common stock on the applicable purchase date. The following table reflects the assumptions used in the Black-Scholes option pricing model to calculate the expense related to the ESPP: Year Ended December 31, 2018 2017 2016 Expected term (in years) 0.5 - 1.0 0.5 - 1.0 0.5 - 1.0 Expected volatility 37% 37 – 40% 42 – 49% Risk-free interest rate 2.0 – 2.6% 0.9 – 1.3% 0.5 – 0.7% Expected dividend yield — — — Grant date fair value per share $ 6.62 – 10.95 $ 4.01 – 5.35 $ 3.58 – 5.49 On March 15, 2016, we issued 192,676 shares of common stock to employees for aggregate proceeds of $2.1 million . The purchase price of the shares of common stock was $10.88 per share, which was discounted in accordance with the terms of the ESPP from the closing price of our common stock on March 15, 2016 of $12.80 . On September 15, 2016, we issued 153,602 shares of common stock to employees for aggregate proceeds of $1.6 million . The purchase price of the shares of common stock was $10.60 per share, which was discounted in accordance with the terms of the ESPP from the closing price of our common stock on March 16, 2016 of $12.47 . On March 15, 2017, we issued 138,085 shares of common stock to employees for aggregate proceeds of $1.5 million . The purchase prices of the shares of common stock were $10.60 and $12.79 per share, which were discounted in accordance with the terms of the ESPP from the closing prices of our common stock on March 16, 2016 of $12.47 and on March 15, 2017 of $15.05 , respectively. On September 15, 2017, we issued 109,144 shares of common stock to employees for aggregate proceeds of $1.4 million . The purchase price of the shares of common stock was $12.96 per share, which was discounted in accordance with the terms of the ESPP from the closing price of our common stock on March 16, 2017 of $15.25 . On March 15, 2018, we issued 123,607 shares of common stock to employees for aggregate proceeds of $1.6 million . The purchase prices of the shares were $12.96 and $14.78 per share, which were discounted in accordance with the terms of the ESPP from the closing prices of our common stock on March 16, 2017 of $15.25 and on September 18, 2017 of $17.39 , respectively. On September 14, 2018, we issued 96,108 shares of common stock to employees for aggregate proceeds of $2.0 million . The purchase prices of the shares were $21.96 and $14.78 per share, which were discounted in accordance with the terms of the ESPP from the closing prices of our common stock on March 16, 2018 of $25.84 and on September 18, 2017 of $17.39 , respectively.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Loss before income taxes included in the consolidated statements of operations was as follows: Year Ended December 31, 2018 2017 2016 (in thousands) United States $ (39,754 ) $ (22,757 ) $ (41,466 ) Foreign (15,325 ) (24,949 ) (7,561 ) Loss before income taxes $ (55,079 ) $ (47,706 ) $ (49,027 ) Income tax expense (benefit) included in the consolidated statements of operations was as follows: Year Ended December 31, 2018 2017 2016 (in thousands) Current: Federal $ 124 $ 333 $ 493 State and local 126 128 61 Foreign 228 163 (656 ) Total current (benefit) expense 478 624 (102 ) Deferred: Federal (285 ) (2,885 ) 98 State and local 16 8 13 Foreign 257 17 (36 ) Total deferred expense (12 ) (2,860 ) 75 Income tax expense (benefit) $ 466 $ (2,236 ) $ (27 ) The reconciliation of income tax expense (benefit) to the amount computed at the federal statutory rate of 21% for the year ended December 31, 2018 and 34% for the years ended December 31, 2017 and 2016 was as follows: Year Ended December 31, 2018 2017 2016 Expected income tax 21.0 % 34.0 % 34.0 % State taxes, net of federal benefit (0.2 ) (0.2 ) (0.1 ) Permanent differences 0.2 (0.4 ) (0.4 ) Stock compensation 9.3 4.6 (1.0 ) Federal research and development credit 1.2 1.0 2.4 Foreign rate differential (1.1 ) (8.7 ) (3.0 ) Change in valuation allowance (32.8 ) (26.1 ) (31.9 ) Other 1.5 0.5 0.1 Total income tax expense (benefit) (0.9 )% 4.7 % 0.1 % On December 22, 2017, the Tax Cuts and Jobs Act of 2017 (Tax Act) was signed into law making significant changes to the Internal Revenue Code. Changes include, but are not limited to, a federal corporate tax rate decrease from 34% to 21% for tax years beginning after December 31, 2017, the transition of U.S. international taxation from a worldwide tax system to a territorial system and a one-time transition tax on the mandatory deemed repatriation of foreign earnings (transition tax). We recorded a one-time income tax benefit of $0.4 million in the fourth quarter of 2017 as a result of the Tax Act. The one-time income tax benefit included $0.2 million related to the remeasurement of certain deferred tax assets and liabilities based on the lower tax rates at which they are expected to reverse in the future. The one-time income tax benefit also included a provisional amount of $0.2 million related to the release of valuation allowance against alternative minimum tax (AMT) credits that we will receive a benefit for in the form an AMT tax refund. We have not recorded any transition tax on foreign earnings as our foreign subsidiaries have an accumulated deficit. The Tax Act requires a U.S. corporation to record taxes on global intangible low-tax income (GILTI) and elect an accounting policy to either 1) recognize GILTI as a current period expense when incurred or 2) to record deferred taxes for the temporary basis differences expected to reverse in the future as GILTI. We did not generate any GILTI during 2018. We have elected to recognize GILTI tax as a period cost when incurred. Additionally, Staff Accounting Bulletin No. 118 (SAB 118) was issued to address the application of U.S. GAAP in situations when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Act. December 22, 2018, marked the end of the measurement period for purposes of SAB 118. As such, we have completed the analysis based on legislative updates relating to the Tax Act currently available which resulted in immaterial SAB 118 tax adjustments in the fourth quarter of 2018. Net deferred tax assets and liabilities, as set forth in the table below, reflect the impact of temporary differences between the amounts of assets and liabilities recorded for financial statement purposes and such amounts measured in accordance with tax laws: As of December 31, 2018 2017 (in thousands) Deferred tax assets: Accruals and reserves $ 397 $ 636 Net operating loss carryforwards 55,457 36,778 Deferred revenue 15,421 11,985 Depreciation 1,542 926 Research and development credits 3,440 2,441 Stock-based compensation 4,851 3,702 Tax credits 932 657 Other 953 557 Total deferred tax assets 82,993 57,682 Deferred tax liabilities: Intangible assets (1,104 ) (616 ) Convertible senior notes (12,537 ) — Deferred contract acquisition and fulfillment costs (9,796 ) — Other (79 ) — Total deferred tax liabilities (23,516 ) (616 ) Less: Valuation allowance (60,130 ) (57,359 ) Net deferred tax liabilities $ (653 ) $ (293 ) As of December 31, 2018 , we have evaluated the need for a valuation allowance on deferred tax assets. In assessing whether the deferred tax assets are realized, management considered whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. Due to our history of generating losses in the United States, the United Kingdom and Ireland, we continue to record a full valuation allowance against our deferred tax assets in these jurisdictions. If we achieve future profitability, a significant portion of these deferred tax assets could be available to offset future income taxes. The valuation allowance increased by $2.8 million for the year ended December 31, 2018 , primarily due to additional operating losses generated during the year partially offset by an increase in deferred tax liabilities associated with our convertible senior notes and deferred contract acquisition and fulfillment costs as a result of the adoption of ASC 606. We plan to permanently reinvest the undistributed earnings of our foreign subsidiaries. If we repatriate these earnings, we may be required to pay U.S. state and local taxes, as well as foreign withholding taxes. As of December 31, 2018 , we had federal and state net operating loss carryforwards of $171.2 million and $118.7 million , respectively. As part of the Tax Act, federal net operating losses generated after December 31, 2017, which total $50.3 million , have no expiration date and will be carried forward indefinitely. The remaining federal and state net operating loss carryforwards expire at various dates beginning in 2021. As of December 31, 2018 , we had foreign net operating loss carryforwards of $93.1 million that can be carried forward indefinitely. We also had federal, state and international research and development credit carryforwards of $2.2 million , $1.1 million and $0.1 million as of December 31, 2018 , respectively. These credit carryforwards expire at various dates beginning in 2023. We believe that a change of ownership within the meaning of Section 382 and 383 of the Internal Revenue Code of 1986, as amended, occurred in 2011 and 2018. Under Section 382 and 383 of the Internal Revenue Code of 1986, as amended, if a corporation undergoes an “ownership change,” generally defined as a greater than 50% change (by value) in its equity ownership over a three-year period, the corporation’s ability to use its pre-change net operating loss carryforwards, or NOLs, and other pre-change tax attributes, such as research and development credits, to offset its post-change income may be limited. The analysis indicates that although an ownership change occurred, Rapid7, Inc.'s U.S. federal net operating losses and research and development credits would not expire before utilization as a result of the ownership change. In the event we have subsequent changes in ownership, net operating losses and research and development credit carryforwards could be limited. We file income tax returns in all jurisdictions in which we operate. We have established reserves to provide for additional income taxes that management believes will more likely or not be due in future years. The reserves have been established based upon our assessment as to the potential exposure. Changes in our reserves for unrecognized income tax benefits are as follows: Amount (in thousands) Balance at December 31, 2016 $ 388 Decreases based on settlements with taxing authorities (343 ) Reductions based on lapse in statute of limitations (16 ) Balance at December 31, 2017 29 Reductions based on lapse in statute of limitations (17 ) Balance at December 31, 2018 $ 12 In the normal course of business, we are subject to examination by federal, state, and foreign jurisdictions, where applicable. The statute of limitations for these jurisdictions is generally three to six years. However, to the extent we utilize net operating losses or other similar carryforward attributes such as credits, the statute remains open to the extent of the net operating losses or credits that are utilized. We have no tax returns under examination as of December 31, 2018 . We record interest and penalties on any income tax liability as income tax expense. We recorded nominal interest and penalties in 2018 , 2017 and 2016 . During the next 12 months, we do not expect any material changes to our uncertain tax positions other than the accrual of interest in the normal course of business.

Net Loss Per Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Net Loss Per Share	Net Loss Per Share The following table summarizes the computation of basic and diluted net loss per share of our common stock for 2018 , 2017 and 2016 : Year Ended December 31, 2018 2017 2016 (in thousands, except share and per share data) Numerator: Net loss $ (55,545 ) $ (45,470 ) $ (49,000 ) Denominator: Weighted-average common shares outstanding, basic and diluted 46,456,825 42,952,950 41,248,473 Net loss per share, basic and diluted $ (1.20 ) $ (1.06 ) $ (1.19 ) The following potentially dilutive securities outstanding, prior to the use of the treasury stock method or if-converted method, have been excluded from the computation of diluted weighted-average shares outstanding for the respective periods below because they would have been anti-dilutive: Year Ended December 31, 2018 2017 2016 Options to purchase common stock 3,713,179 4,684,954 4,580,375 Unvested restricted stock 21,677 210,083 585,004 Unvested restricted stock units 2,773,773 1,988,509 734,577 Shares to be issued under ESPP 74,634 79,551 91,815 Total 6,583,263 6,963,097 5,991,771 Additionally, the 5.5 million shares underlying the conversion option of the Notes are not considered in the calculation of diluted net loss per share as the effect would be anti-dilutive. The Notes are not convertible as of December 31, 2018 . We expect to settle the principal amount of the Notes in cash and therefore use the treasury stock method for calculating any potential dilutive effect of the conversion spread on diluted net income per share, if applicable. The conversion spread will have a dilutive impact on diluted net income per share when the average market price of our common stock for a given period of time exceeds the initial conversion price of $41.59 per share for the Notes.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies (a) Leases We have operating lease commitments for our facilities that expire at various dates through 2029. For operating leases that contain rent escalation or rent concession provisions, we record the total rent expense on a straight-line basis over the term of the lease. We record the difference between the rent paid and the straight-line rent as a deferred rent liability on the accompanying consolidated balance sheets. Further, landlord incentives, such as tenant improvement allowances, are deferred and amortized on a straight-line basis over the lease term as a reduction of rent expense. In addition to rental payments, certain leases require additional payments for real estate taxes, common area maintenance and insurance, which are expensed when incurred and not included in the future minimum payments table noted below. Rent expense was $7.5 million , $5.7 million and $5.0 million for 2018 , 2017 and 2016 , respectively. The future minimum payments under non-cancellable operating leases as of December 31, 2018 are as follows: 2019 $ 9,899 2020 11,616 2021 10,933 2022 11,054 2023 11,136 Thereafter 53,648 Total $ 108,286 (b) Purchase Obligations As of December 31, 2018 , we have non-cancellable firm purchase commitments relating to cloud infrastructure services, including with Amazon Web Services, software subscriptions and the build-out of our new corporate headquarters that will be payable in the amounts of $42.5 million , $23.6 million , $25.8 million , $0.2 million , $0.1 million and $0.1 million for 2019, 2020, 2021, 2022, 2023 and thereafter. (c) Letters of Credit As of December 31, 2018 , we had a total of $8.2 million in letters of credit outstanding as collateral for certain office space leases and a corporate credit card program. These irrevocable letters of credit, which are not included in the table of contractual obligations above, are unsecured and are expected to remain in effect, in some cases, until 2029. (d) Warranty We provide limited product warranties. Historically, any payments made under these provisions have been immaterial. (e) Litigation and Claims In November 2016, our wholly-owned subsidiary, Rapid7 LLC, and two of our then executive officers were named as defendants in a class action lawsuit which alleged violations of certain Massachusetts wage and hour laws. In the fourth quarter of 2018, we agreed to a settlement in the amount of $0.6 million . In October 2018, Finjan, Inc. (Finjan) filed a complaint against us and our wholly-owned subsidiary, Rapid7 LLC, in the United States District Court, District of Delaware, alleging patent infringement of seven patents held by them. In the complaint, Finjan sought unspecified damages, attorneys' fees and injunctive relief. We intend to vigorously contest Finjan's claims. This litigation is still in its early stages and the final outcome, including our liability, if any, with respect to Finjan's claims, is uncertain. Regardless of the outcome, litigation can have an adverse impact on us because of defense and settlement costs, diversion of management resources and other factors. In addition, from time to time, we may be a party to litigation or subject to claims incident to the ordinary course of business. Although the results of litigation and claims cannot be predicted with certainty, we currently believe that the final outcome of these ordinary course matters will not have a material adverse effect on our business. Regardless of the outcome, litigation can have an adverse impact on us because of defense and settlement costs, diversion of management resources and other factors. (f) Indemnification Obligations We agree to standard indemnification provisions in the ordinary course of business. Pursuant to these provisions, we agree to indemnify, hold harmless and reimburse the indemnified party for losses suffered or incurred by the indemnified party, generally our customers, in connection with any United States patent, copyright or other intellectual property infringement claim by any third party arising from the use of our products or services in accordance with the agreement or arising from our gross negligence, willful misconduct or violation of the law (provided that there is not gross or willful misconduct on the part of the other party) with respect to our products or services. The term of these indemnification provisions is generally perpetual from the time of execution of the agreement. We carry insurance that covers certain third-party claims relating to our services and limits our exposure. We have never incurred costs to defend lawsuits or settle claims related to these indemnification provisions. As permitted under Delaware law, we have entered into indemnification agreements with our officers and directors, indemnifying them for certain events or occurrences while they serve as officers or directors of the company.

Employee Benefit Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
Employee Benefit Plan	Employee Benefit Plan In December 2008, we established a discretionary 401(k) plan in which all full-time U.S. employees above the age 18 are eligible to participate after they have been employed for us for 90 days following the applicable date of hire. Matching contributions to the 401(k) plan can be made at our discretion. In 2018 and 2017 , we made discretionary contributions of $2.0 million and $1.4 million , respectively, to the plan. We did not make any contributions to the 401(k) plan in 2016 .

Segment Information and Informa

Segment Information and Information about Geographic Areas	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Segment Information and Information about Geographic Areas	Segment Information and Information about Geographic Areas We operate in one segment. Our chief operating decision maker is our Chief Executive Officer, who makes operating decisions, assesses performance and allocates resources on a consolidated basis. Net revenues by geographic area presented based upon the location of the customer are as follows: Year Ended December 31, 2018 2017 2016 (in thousands) North America $ 207,727 $ 170,667 $ 134,988 Other 36,364 30,273 22,449 Total $ 244,091 $ 200,940 $ 157,437 Of the total net revenues generated in North America, 96% , 93% and 95% was generated in the United States in 2018 , 2017 and 2016 , respectively. Property and equipment, net by geographic area as of December 31, 2018 and 2017 is presented in the table below: As of December 31, 2018 2017 (in thousands) United States $ 16,311 $ 7,182 Other 1,212 1,407 Total $ 17,523 $ 8,589

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2018
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions In October 2015, Intel Security announced the end-of-sale for the McAfee Vulnerability Manager to customers and partners, effective January 11, 2016, with end-of-life to follow, and announced that we were named their exclusive vulnerability management partner. Under the terms of the commercial agreement, we incur partner referral fees as customers transition from McAfee Vulnerability Manager to Nexpose. On February 6, 2017, Michael Berry, a member of our board of directors, became the chief financial officer of Intel Security (McAfee). For the years ended December 31, 2018 , 2017 and 2016, we made payments for partner referral fees of $1.6 million , $1.9 million and $1.7 million to Intel Security.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Basis of Presentation and Consolidation	Basis of Presentation and Consolidation The accompanying consolidated financial statements include our results of operations and those of our wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated in consolidation. The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP).
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates, judgments and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Significant items subject to such estimates and assumptions include the determination of the estimated economic life of perpetual licenses for revenue recognition, the determination of standalone selling prices in revenue transactions with multiple performance obligations, the estimated period of benefit for deferred contract acquisition and fulfillment costs, the valuation of allowance for doubtful accounts, the valuation of stock-based compensation and the valuation of intangible assets acquired in a business combination. We base our estimates on historical experience and on various other assumptions that we believe are reasonable. Actual results could differ from those estimates.
Revenue Recognition	Revenue Recognition We generate products revenue from the sale of (1) cloud-based subscriptions for our InsightIDR, InsightVM, InsightAppSec and InsightConnect products, (2) managed services offerings which utilize our products and (3) term or perpetual software licenses for our Nexpose, Metasploit, AppSpider and Komand products, and associated content subscriptions for our Nexpose and Metasploit products. We also generate appliance revenue that is included in our products revenue and is associated with hardware sold with our Nexpose product to certain customers. We generate maintenance and support revenue associated with customers’ purchases of our software licenses for Nexpose, Metasploit, AppSpider and Komand. We generate professional service revenue from the sale of our deployment and training services related to our solutions, incident response services and security advisory services. Our deployment services educate and assist our customers on the best use and best practices to deploy our solutions. We adopted Financial Accounting Standards Board (FASB) Accounting Standards Update (ASU) 2014-09, Revenue from Contracts with Customers (Topic 606) (ASC 606) on January 1, 2018 using the modified retrospective method. Under this method of adoption, we recognized the cumulative effect of initially applying the new revenue standard as an adjustment to the opening balance of accumulated deficit. Comparative prior periods were not adjusted. In accordance with ASC 606, revenue is recognized when a customer obtains control of promised products or services. The amount of revenue recognized reflects the consideration that we expect to be entitled to receive in exchange for these products or services. To achieve the core principle of this standard, we apply the following five steps: 1) Identify the contract with a customer We consider the terms and conditions of the contracts and our customary business practices in identifying our contracts under ASC 606. We determine we have a contract with a customer when the contract is approved, we can identify each party’s rights regarding the services to be transferred, we can identify the payment terms for the services, and we have determined the customer has the ability and intent to pay and the contract has commercial substance. We apply judgment in determining the customer’s ability and intent to pay, which is based on a variety of factors, including the customer’s historical payment experience or, in the case of a new customer, credit and financial information pertaining to the customer. 2) Identify the performance obligations in the contract Performance obligations promised in a contract are identified based on the products and services that will be transferred to the customer that are both capable of being distinct, whereby the customer can benefit from the product or service either on its own or together with other resources that are readily available from third parties or from us, and are distinct in the context of the contract, whereby the transfer of the products or services is separately identifiable from other promises in the contract. 3) Determine the transaction price The transaction price is determined based on the consideration to which we expect to be entitled in exchange for transferring products or services to the customer. Variable consideration is included in the transaction price if, in our judgment, it is probable that no significant future reversal of cumulative revenue under the contract will occur. In instances where the timing of revenue recognition differs from the timing of invoicing, we have determined our contracts generally do not include a significant financing component. The primary purpose of our invoicing terms is to provide customers with simplified and predictable ways of purchasing our products and services, not to receive financing from our customers or to provide customers with financing. Examples include invoicing at the beginning of a subscription term with revenue recognized ratably over the contract period. 4) Allocate the transaction price to performance obligations in the contract If the contract contains a single performance obligation, the entire transaction price is allocated to the single performance obligation. Contracts that contain multiple performance obligations require an allocation of the transaction price to each performance obligation based on a relative standalone selling price (“SSP”). 5) Recognize revenue when or as we satisfy a performance obligation Revenue is recognized at the time the related performance obligation is satisfied by transferring the promised product or service to a customer. Revenue is recognized when control of the products or services are transferred to our customers, in an amount that reflects the consideration that we expect to receive in exchange for those products or services. The following table summarizes revenue from contracts with customers for the year ended December 31, 2018 : Year Ended (in thousands) Subscription revenue $ 137,442 Term and perpetual software licenses 28,200 Maintenance and support 42,223 Professional services 33,297 Other 2,929 Total revenue $ 244,091 The following table summarizes the revenue by region based on the shipping address of customers who have contracted to use our product or service for the year ended December 31, 2018 : Year Ended (in thousands) United States $ 199,852 All other 44,239 Total revenue $ 244,091 Subscription Revenue Subscription revenue consists of revenue from our cloud-based subscription, managed services offerings and content subscriptions associated with our software licenses. • We generate cloud-based subscription revenue primarily from sales of subscriptions to access our cloud platform, together with related support services to our customers. These arrangements do not provide the customer with the right to take possession of our software operating on our cloud platform at any time. Instead, customers are granted continuous access to our cloud platform over the contractual period. Revenue is recognized over time on a ratable basis over the contract term beginning on the date that our service is made available to the customer. Our cloud-based subscription contracts generally have a term of 1 year which is billed in advance and non-cancellable. • Managed services offerings consist of fees generated when we operate our software and provide our capabilities on behalf of our customers. Revenue is recognized on a ratable basis over the contract term beginning on the date that our service is made available to the customer. Our managed services offerings generally have a term of 1 year which is billed in advance and non-cancellable. • Revenue related to our content subscriptions associated with our software licenses is recognized ratably over the contractual period. • Some of our customers have the option to purchase additional subscription and support services at a stated price. These options generally do not provide a material right as they are priced at our SSP. Certain subscription contracts contain service level commitments, which entitle our customers to receive service credits and, in certain cases, refunds, if our services do not meet certain levels. These service credits and refunds represent variable consideration. We have historically not experienced any significant incidents affecting the defined levels of reliability and performance as required by our subscription contracts and accordingly, no estimated refunds have been considered in the allocation of the transaction price. Term and Perpetual Software Licenses For our perpetual software licenses where the utility to the customer is dependent on the continued delivery of content subscriptions, the content subscription renewal options result in a material right with respect to the perpetual software license. As a result, the revenue attributable to the perpetual software license is recognized ratably over the customer’s estimated economic life of five years , which represents a longer period of time in comparison to the initial contractual period of maintenance and support. The estimated economic life of five years represents the period which the customer is expected to benefit from the material right. We estimated this period of benefit by taking into consideration several factors, including the terms and conditions of our customer contracts and renewals and the expected useful life of our technology. For our term software licenses where the utility to the customer is dependent on the continued delivery of content subscriptions, we recognize the license revenue over the contractual term of the arrangement as a material right does not exist. For our term and perpetual software licenses which are not dependent on the continued delivery of content subscriptions, the license is considered distinct from the maintenance and support, and we therefore recognize revenue attributable to the license at the time of delivery. Maintenance and Support Maintenance and support services are sold with our perpetual and term software licenses. As maintenance and support services are distinct from the perpetual and term software license, revenue attributable to maintenance and support services is recognized ratably over the contractual period. Professional Services All of our professional services are considered distinct performance obligations when sold stand alone or with other products. These contracts generally have terms of one year or less. For the majority of these contracts, revenue is recognized over time based upon the proportion of work performed to date. Other Other revenue primarily includes revenue from delivery of appliances and other miscellaneous revenue. Contracts with Multiple Performance Obligations The majority of our contracts with customers contain multiple performance obligations. For these contracts, we account for individual performance obligations separately if they are considered distinct. The transaction price is allocated to the separate performance obligations on a relative SSP basis. We determine SSP based on our overall pricing objectives, taking into consideration market conditions and other factors, including the geographic locations of our customers and selling method (i.e., partner or direct). Contract Balances Contract liabilities consist of deferred revenue and include payments received in advance of performance under the contract. Such amounts are recognized as revenue over the contractual period consistent with the above methodology. For the year ended December 31, 2018 , we recognized revenue of $135.6 million that was included in the corresponding contract liability balance at the beginning of the period presented. Deferred revenue that will be realized during the succeeding 12-month period is recorded as current, and the remaining deferred revenue is recorded as non-current. We receive payments from customers based upon contractual billing schedules. Accounts receivable are recorded when the right to consideration becomes unconditional. Contract assets, or unbilled receivables, include amounts related to our contractual right to consideration for both completed and partially completed performance obligations that may not have been invoiced. As of January 1, 2018 and December 31, 2018 , contract assets of $0.3 million and $0.8 million , respectively, are included in prepaid expenses and other current assets in our consolidated balance sheet. Transaction Price Allocated to the Remaining Performance Obligations The following table includes estimated revenue expected to be recognized in the future related to performance obligations that are unsatisfied or partially unsatisfied as of December 31, 2018 . The estimated revenues do not include unexercised contract renewals. 2019 2020 2021 and thereafter (in thousands) Subscription revenue $ 129,539 $ 37,471 $ 980 Term and perpetual software licenses 22,880 20,776 4,043 Maintenance and support 26,966 6,536 110 The amounts presented in the table above primarily consist of fixed fees which are typically recognized ratably as the performance obligation is satisfied. As of December 31, 2018 , the estimated revenue expected to be recognized in the future related to performance obligations that are unsatisfied or partially unsatisfied associated with professional services was $12.0 million . We will recognize this revenue as the professional services are completed, which is expected to occur within the next 12 months or less. Transition Disclosures For periods prior to January 1, 2018, we recognized revenue in accordance with FASB ASC Topic 605, Revenue Recognition (ASC 605). In accordance with the modified retrospective method transition requirements, we will present the financial statement line items impacted and adjusted to compare to presentation under ASC 605 for each of the interim and annual periods during the first year of our adoption of ASC 606. The following tables summarize the impact as of and for the year ended December 31, 2018 : As of December 31, 2018 Balance Sheet As Reported under ASC 606 Proforma as if ASC 605 was in effect (in thousands) Cash and cash equivalents $ 99,565 $ 99,565 Short-term investments 159,210 159,210 Accounts receivable, net 74,935 74,935 Deferred contract acquisition and fulfillment costs, current portion 12,321 — Prepaid expenses and other current assets 9,746 9,281 Long-term investments 44,892 44,892 Property and equipment, net 17,523 17,523 Goodwill 88,420 88,420 Intangible assets, net 23,955 23,955 Deferred contract acquisition and fulfillment costs, non-current portion 27,634 — Other assets 1,168 1,168 Total assets $ 559,369 $ 518,949 Accounts payable 7,048 7,048 Accrued expenses 37,376 37,376 Deferred revenue, current portion 189,855 193,763 Other current liabilities 707 707 Convertible senior notes, net 174,688 174,688 Deferred revenue, non-current portion 58,716 41,658 Other long-term liabilities 3,660 2,912 Total liabilities 472,050 458,152 Common stock 476 476 Treasury stock (4,764 ) (4,764 ) Additional paid-in-capital 556,223 556,223 Accumulated other comprehensive loss (31 ) (31 ) Accumulated deficit (464,585 ) (491,107 ) Total stockholders’ equity 87,319 60,797 Total liabilities and stockholders’ equity $ 559,369 $ 518,949 Total reported assets were $40.4 million greater than the proforma balance sheet, which assumes the previous guidance remained in effect as of December 31, 2018 , largely due to deferred contract acquisition and fulfillment costs of $40.0 million . Total reported liabilities were $13.9 million greater than the proforma balance sheet primarily due to changes in deferred revenue and deferred tax liabilities. Year Ended December 31, 2018 Statement of Operations As Reported under ASC 606 Proforma as if ASC 605 was in effect (in thousands, except share and per share data) Revenue: Products $ 168,571 175,146 Maintenance and support 42,223 45,767 Professional services 33,297 35,010 Total revenue 244,091 255,923 Cost of revenue: Products 39,810 39,761 Maintenance and support 7,678 7,678 Professional services 23,595 23,577 Total cost of revenue 71,083 71,016 Total gross profit 173,008 184,907 Operating expenses: Research and development 67,743 67,743 Sales and marketing 123,310 136,167 General and administrative 34,993 34,993 Total operating expenses 226,046 238,903 Loss from operations (53,038 ) (53,996 ) Other income (expense), net: Interest income 3,229 3,229 Interest expense (4,934 ) (4,934 ) Other income (expense), net (336 ) (336 ) Loss before income taxes (55,079 ) (56,037 ) Provision for income taxes 466 157 Net loss $ (55,545 ) $ (56,194 ) Net loss per share, basic and diluted $ (1.20 ) $ (1.21 ) Weighted-average common shares outstanding, basic and diluted 46,456,825 46,456,825 The following summarizes the significant changes on the consolidated statement of operations for the year ended December 31, 2018 as a result of the adoption of ASC 606 on January 1, 2018 compared to if we had continued to recognize revenue under ASC 605: • Products revenue decreased $6.6 million for the year ended December 31, 2018 under ASC 606 primarily due to perpetual licenses revenue which are dependent on the continued delivery of content subscriptions and the change in the allocation of contract consideration to the relative fair value method under ASC 606 from the residual method under ASC 605. As a result of the allocation change, more contract consideration is allocated to license revenue under ASC 606. Given the utility of certain of our perpetual license products are dependent on the continued delivery of content subscriptions, the content subscription renewal option results in a material right with respect to the perpetual license. As a result, revenue allocated to the perpetual license is recognized ratably over the customer's estimated economic life of five years rather than over the contractual period of maintenance and support, typically one to three years . • Maintenance and support revenue decreased $3.5 million for the year ended December 31, 2018 under ASC 606 primarily due to the change in the allocation of contract consideration to the relative fair value method under ASC 606 from the residual method under ASC 605. As a result of the allocation change, more contract consideration is allocated to license revenue under ASC 606. • Professional services revenue decreased $1.7 million for the year ended December 31, 2018 under ASC 606 primarily due to the fact that our professional services are sold together with term or perpetual licenses. Under ASC 606, the professional services represent distinct performance obligations and therefore are recognized as services are performed. Under ASC 605, professional services sold together with term or perpetual licenses were recognized ratably over the contractual period of maintenance and support. • Sales and marketing expense decreased $12.9 million for the year ended December 31, 2018 under ASC 606 primarily due to the capitalization of commissions considered direct and incremental costs to obtain a contract partially offset by amortization of capitalized commissions. • Provision for income taxes increased $0.3 million for the year ended December 31, 2018 under ASC 606 due to additional deferred taxes for the temporary differences between the accounting and tax treatments of capitalized costs to obtain or fulfill a contract. Year Ended December 31, 2018 Statement of Cash Flows As Reported under ASC 606 Proforma as if ASC 605 was in effect (in thousands) Net loss $ (55,545 ) $ (56,194 ) Adjustments to reconcile net loss to net cash provided by operating activities 43,443 43,125 Changes in operating assets and liabilities: Accounts receivable (1,685 ) (1,685 ) Deferred contract acquisition and fulfillment costs (12,790 ) — Prepaid expenses and other assets (287 ) 146 Accounts payable 3,675 3,675 Accrued expenses 6,018 6,018 Deferred revenue 22,870 10,614 Other liabilities 367 367 Net cash provided by operating activities $ 6,066 $ 6,066 The adoption of ASC 606 resulted in offsetting changes in operating assets and liabilities and had no impact on net cash flow from operations. Legacy Revenue Accounting Policy For periods prior to January 1, 2018, revenue was recognized in accordance with ASC 605. Under ASC 605, revenue was recognized when all of the following were met: • Persuasive evidence of an arrangement existed . Binding agreements or purchase orders were generally evidence of an arrangement. • Delivery had occurred . Delivery occurred (1) upon delivery of the software license key or when the customer had access to the software product or (2) when we performed the services. • The sales price was fixed or determinable . Fees were considered fixed and determinable when the fees were contractually agreed upon with the customer. • Collectability was probable . Collectability was deemed probable based on review of a number of factors, including creditworthiness and customer payment history. If collectability was not probable, revenue was deferred until collection became probable, which was generally upon the receipt of payment. Substantially all of our software licenses were sold in multiple-element arrangements that included maintenance and support and content subscriptions, and in addition could include cloud-based subscriptions, professional services and/or managed services. All of these elements were considered to be software elements other than cloud-based subscriptions and managed services which were non-software elements. Non-software elements included in multiple-element arrangements consist of a single deliverable that had stand-alone value and represented a single unit of accounting. We determined that we did not have vendor-specific objective evidence, or VSOE, of the selling price for the elements comprising these multiple-element arrangements as our software licenses were generally not sold on a stand-alone basis and we purposefully employed variable pricing for our offerings in order to meet customer purchase requirements along the multiple price points of the demand curve. When all of the elements of a multiple-element arrangement were software elements, the revenue for software licenses and any other products and services that were sold along with the license was generally deferred on our balance sheet and recognized as revenue on our consolidated statements of operations ratably over the contractual period of the maintenance and support, typically one to three years, which was longer than the period over which the professional services were performed. Revenue recognition began upon delivery of the software license, assuming that all other criteria for revenue recognition had been met. When a multiple-element arrangement included both software elements and non-software elements, the total arrangement consideration was first allocated between the software elements and the non-software elements based on the selling price hierarchy, which included (1) VSOE, if available, (2) third-party evidence, or TPE, if VSOE was not available or (3) best estimate of selling price, or BESP, if neither VSOE nor TPE was available. We were not able to establish a selling price for any element using VSOE or TPE. We determined BESP by considering our overall pricing objectives and market conditions. Significant pricing practices taken into consideration included our discounting practices, the size and volume of our transactions, our price lists, our go-to-market strategy, historical standalone sales and contract prices. The determination of BESP was made in consultation with, and was approved by, our management. The portion of the consideration allocated to the non-software elements was recognized ratably over the service period of the non-software elements, assuming all other criteria for revenue recognition had been met. The portion of the consideration allocated to software elements was recognized as described above. With respect to our managed services and cloud-based subscription offerings sold on a stand-alone basis, we recognized revenue ratably over the term of the managed service agreement or subscription, assuming that the other criteria for revenue recognition were met. We recognized revenue from professional services sold on a stand-alone basis as those services were rendered. For purposes of disclosing revenue by class, we allocated the arrangement consideration for multiple-element software arrangements among the individual elements utilizing BESP, as we did not have VSOE or TPE of selling price for any of the elements.
Cash and Cash Equivalents	Cash and Cash Equivalents We consider all highly liquid instruments with original maturities of three months or less at the date of purchase to be cash equivalents. Cash and cash equivalents are recorded at cost, which approximates fair value.
Investments	Investments We classify our investments as available-for-sale and record these investments at fair value. We currently invest primarily in commercial paper, corporate bonds, agency bonds, U.S. Government agencies and asset-backed securities. Investments with an original maturity of greater than three months at the date of purchase and less than one year from the date of the balance sheet are classified as short-term and those with maturities of more than one year from the date of the balance sheet are classified as long-term in the consolidated balance sheet. Additionally, we do not invest in any securities with contractual maturities greater than 24 months. Unrealized gains and losses that are considered temporary are reported as a component of other comprehensive loss. Realized gains and losses are determined based on the specific identification method, and are reflected in our consolidated statements of operations. We regularly review our investment portfolio to identify and evaluate investments that have indicators of possible impairment. Factors considered in determining whether a loss is other-than-temporary include, but are not limited to: the length of time and extent a security’s fair value has been below its cost, the financial condition and near-term prospects of the investee, the credit quality of the security’s issuer, likelihood of recovery and our intent and ability to hold the security for a period of time sufficient to allow for any anticipated recovery in value. For our debt instruments, we also evaluate whether we have the intent to sell the security or it is more likely than not that we will be required to sell the security before recovery of its cost basis.
Accounts Receivable and Allowance for Doubtful Accounts	Accounts Receivable and Allowance for Doubtful Accounts Accounts receivable are recorded at the invoiced amount, net of allowances for doubtful accounts. Management regularly reviews the adequacy of the allowance for doubtful accounts by considering the age of outstanding invoices, the customer’s expected ability to pay and the collection history, when applicable, to determine whether an allowance is appropriate. Accounts receivable are charged against the allowance for doubtful accounts after all means of collection have been exhausted and the potential for recovery is considered remote. Additions to the allowance for doubtful accounts are recorded in general and administrative expense in the consolidated statement of operations. We do not have any off-balance sheet credit exposure related to our customers.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that potentially expose us to concentrations of credit risk consist primarily of cash and cash equivalents, accounts receivable and short-term and long-term investments. As of December 31, 2018 and 2017 , $58.6 million and $0.1 million , respectively, of our cash equivalents were invested in money market funds, U.S. Government agencies and commercial paper. Deposits held with banks may exceed the amount of insurance provided on such deposits. We have not experienced any losses in such accounts and believe that we are not exposed to any significant risk. We provide credit to customers in the normal course of business. Collateral is not required for accounts receivable, but ongoing credit evaluations of customers’ financial condition are performed. We maintain reserves for potential credit losses. No single customer, including channel partners, accounted for 10% or more of our total revenues in 2018 , 2017 or 2016 or accounts receivable as of December 31, 2018 or 2017 . Our short-term and long-term investments primarily consist of commercial paper, corporate bonds, agency bonds, U.S. Government agencies and asset-backed securities. All of our investments are highly-rated by credit rating agencies and are issued by organizations with reputable credit, and therefore bear minimal credit risk.
Property and Equipment	Property and Equipment Property and equipment are recorded at cost and depreciated over their estimated useful lives using the straight-line method.
Software Development Costs	Software Development Costs Software development costs associated with the development of products for sale are recorded to research and development expense until technological feasibility has been established for the product. Once technological feasibility is established, all software costs are capitalized until the product is available for release to customers. To date, the software development costs have not been capitalized as we believe our current software development process is essentially completed concurrently with the establishment of technological feasibility. As such, these costs are expensed as incurred and recognized in research and development expenses in our consolidated statements of operations. With respect to software developed for internal use, we capitalize qualifying internal costs, such as payroll and benefits of those employees directly associated with the development of the software, and other qualifying consulting costs. Costs incurred during the preliminary planning and evaluation and post implementation stages of the project are expensed as incurred. Costs incurred during the application development stage of the project are capitalized. We capitalized $3.3 million , $1.2 million and $0 of costs related to software developed for internal use in the years ended December 31, 2018, 2017 and 2016, respectively. Total unamortized costs relating to software developed for internal use was $3.4 million and $1.1 million as of December 31, 2018 and 2017 , respectively.
Long-Lived Assets	Long-Lived Assets We evaluate our long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying value of these assets may not be recoverable. When such events or changes in circumstances occur, recoverability of these assets is measured by a comparison of the carrying value of an asset to the future net undiscounted cash flows directly associated with the asset. If assets are considered to be impaired, the impairment recognized is the amount by which the carrying value exceeds the fair value of the asset. We use a discounted cash flow approach or other methods, if appropriate, to assess fair value.
Intangible Assets	For the year ended December 31, 2018 , we determined there were no indicators of impairment of our long-lived assets.
Business Combinations	Business Combinations We recognize tangible and intangible assets acquired and liabilities assumed in a business combination based on their estimated fair values. Determining these fair values requires management to make significant estimates and assumptions, especially with respect to intangible assets. The excess of the purchase price for acquisitions over the fair value of the net assets acquired, including other intangible assets, is recorded as goodwill. While we use our best estimates and assumptions as part of the purchase price allocation to accurately value assets acquired and liabilities assumed at the acquisition date, our estimates are inherently uncertain and subject to refinement. As a result, during the measurement period, which may be up to one year from the acquisition date, we record adjustments to the assets acquired and liabilities assumed with the corresponding offset to goodwill to the extent that we identify adjustments to the preliminary purchase price allocation. Upon the conclusion of the measurement period or final determination of the values of assets acquired or liabilities assumed, whichever comes first, any subsequent adjustments are recorded to the consolidated statements of operations.
Goodwill	Goodwill Goodwill is an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Goodwill is not amortized but is tested for impairment at least annually or more frequently when events or circumstances occur that indicate that it is more likely than not that an impairment has occurred. We test goodwill for impairment on the last day of each fiscal year and whenever events or changes in circumstances indicate that the carrying amount of this asset may exceed its fair value. For our goodwill impairment analysis, we operate with a single reporting unit. To test goodwill impairment, we perform a single-step goodwill impairment test to identify potential goodwill impairment. The single-step impairment test begins with an estimation of the fair value of a reporting unit. Goodwill impairment exists when a reporting unit’s carrying value exceeds its fair value. In performing the single step of the goodwill impairment testing and measurement process, we estimated the fair value of our single reporting unit using our market capitalization. Based upon our assessment performed as of December 31, 2018 , we concluded the fair value of our single reporting unit exceeded its' carrying value and there was no impairment of goodwill.
Foreign Currency	Foreign Currency The functional currency of our foreign subsidiaries is the U.S. dollar. We translate all monetary assets and liabilities denominated in foreign currencies into U.S. dollars using the exchange rates in effect at the balance sheet dates and non-monetary assets and liabilities using historical exchange rates. Foreign currency denominated expenses are re-measured using the average exchange rates for the period. Foreign currency transaction and re-measurement gains and losses are included in other income (expense), net. In 2018, 2017 and 2016, we recorded nominal foreign currency transactional gains (losses). In 2018, 2017 and 2016, we recorded foreign currency re-measurement gains (losses) of $(0.8) million, $0.4 million and $(0.1) million , respectively.
Stock-Based Compensation	Stock-Based Compensation We measure and recognize compensation expense for all stock options, restricted stock awards (RSAs), restricted stock units (RSUs) and common stock issued pursuant to our employee stock purchase plan (ESPP) based on the estimated fair value of the award on the grant date. Stock-based compensation expense is recognized on a straight-line basis over the requisite service period, which is generally the same as the vesting period. Beginning January 1, 2017 with the adoption of ASU 2016-09, we elected to recognize forfeitures as they occur, and no longer estimate a forfeiture rate when calculating the stock-based compensation expense.
Deferred Contract Acquisition and Fulfillment Costs	Deferred Contract Acquisition and Fulfillment Costs In connection with our adoption of ASC 606, we capitalize commission expenses paid to internal sales personnel and partner referral fees that are incremental costs to obtaining customer contracts. These costs are recorded as deferred contract acquisition costs in the consolidated balance sheets. Costs to obtain a contract for a new customer, up-sell or cross-sell are amortized on a straight-line basis over an estimated period of benefit of five years as sales commissions on initial sales are not commensurate with sales commissions on contract renewals. We determined the estimated period of benefit by taking into consideration the contractual term and expected renewals of customer contracts, our technology and other factors, including the fact that commissions paid on renewals are not commensurate with commissions paid on initial sales transactions. We periodically review the carrying amount of deferred contract acquisition costs to determine whether events or changes in circumstances have occurred that could impact the period of benefit. Commissions paid relating to contract renewals are deferred and amortized on a straight-line basis over the related renewal period. Costs to obtain a contract for professional services arrangements are expensed as incurred in accordance with the practical expedient as the contractual period of our professional services arrangements are one year or less. Amortization expense associated with deferred contract acquisition costs is recorded to sales and marketing expense in our consolidated statements of operations. We capitalize costs incurred to fulfill our contracts that relate directly to the contract, are expected to generate resources that will be used to satisfy our performance obligations and are expected to be recovered through revenue generated under the contract. Contract fulfillment costs are amortized on a straight-line basis over the estimated period of benefit and recorded as cost of products in our consolidated statement of operations. The following table summarizes the activity of the deferred contract acquisition and fulfillment costs for the year ended December 31, 2018 : Year Ended (in thousands) Beginning balance $ 27,165 Capitalization of contract acquisition and fulfillment costs 22,765 Amortization of deferred contract acquisition and fulfillment costs (9,975 ) Ending balance $ 39,955 For periods prior to January 1, 2018, under ASC 605, sales commissions were recognized in the period that the commissions were earned by our employees, which was typically upon signing of an arrangement. Under our sales commission policy, the amount of sales commissions expense attributable to the sales arrangement signed in the period was recognized fully in that period; however, the revenue from the sales arrangement was generally recognized ratably over the contractual period of the applicable agreement.
Advertising	Advertising Advertising costs are expensed as incurred, and are recorded in sales and marketing expense in our consolidated statement of operations. We incurred $8.9 million , $8.4 million and $6.0 million in advertising expense in 2018 , 2017 and 2016 , respectively.
Income Taxes	Income Taxes Income taxes are accounted for using the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for differences between the financial statement carrying amounts of existing assets and liabilities and their respective income tax bases, and operating loss and tax credit carryforwards using tax rates expected to be in effect in the years in which the differences are expected to reverse. Deferred tax assets are reduced by a valuation allowance if it is more likely than not that some or all of the deferred tax assets will not be realized in the future. We recognize tax benefits from uncertain tax positions if it is more likely than not that the tax position will be sustained on examination by the taxing authorities based on the technical merits of the position. Interest and penalties associated with such uncertain tax positions are classified as a component of income tax expense.
Net Loss per Share	Net Loss per Share Basic net loss per share is computed by dividing our net loss by the weighted-average number of common shares used in the loss per share calculation during the period. Diluted net loss per share is computed by giving effect to all potentially dilutive securities, including stock options, RSAs, RSUs, the impact of our ESPP and the impact of the conversion spread of our consolidated senior notes (Notes). Basic and diluted net loss per share was the same for all periods presented as the inclusion of all potentially dilutive securities outstanding was anti-dilutive.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Accounting Pronouncements Recently Adopted In June 2018, the FASB issued ASU 2018-07, Compensation-Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting , which expands the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from non-employees, with certain exceptions. We adopted this standard on a prospective basis during the fourth quarter of 2018. There was no impact to our consolidated financial statements as a result of the adoption. In May 2017, the FASB issued ASU 2017-09, Compensation-Stock Compensation (Topic 718): Scope of Modification Accounting , clarifying when a change to the terms or conditions of a share-based payment award must be accounted for as a modification. The ASU required modification accounting if the fair value, vesting condition or the classification of the award is not the same immediately before and after a change to the terms and conditions of the award. We adopted this standard on a prospective basis on January 1, 2018. There was no impact to our consolidated financial statements as a result of the adoption. In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash , which provided guidance on the treatment of restricted cash in the statements of cash flows. Amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. We adopted this standard in the first quarter of 2018 utilizing the retrospective transition method. The presentation of restricted cash in the consolidated statements of cash flows was adjusted as a result of adopting this new standard. In October 2016, the FASB issued ASU 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory . The ASU is intended to improve the accounting for the income tax consequences of intra-entity transfers of assets other than inventory. Current GAAP prohibits the recognition of current and deferred income taxes for an intra-entity asset transfer until the asset has been sold to an outside party. The ASU will allow an entity to recognize the income tax consequences of these transfers when the transfers occur. We adopted this standard on January 1, 2018 and there was no impact to our consolidated financial statements as a result of the adoption. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) , which replaced the revenue recognition requirements in FASB ASC Topic 605, Revenue Recognition . The new revenue standard outlines a single, comprehensive model for accounting for revenue from contracts with customers and requires more detailed disclosure to enable users of financial statements to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from such contracts. The new revenue standard provides a five-step analysis of transactions to determine when and how revenue is recognized. The core principle is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods and services. We adopted ASC 606 on January 1, 2018 using the modified retrospective method. Under this method of adoption, we recognized the cumulative effect of initially applying the new revenue standard as an adjustment to the opening balance of accumulated deficit. Comparative prior year periods were not adjusted. As a result of applying the modified retrospective method to adopt ASC 606, the following adjustments were made to the consolidated balance sheet as of January 1, 2018: As Reported Adjustments Adjusted under ASC 606 December 31, 2017 Term and Perpetual License Professional Services Other Costs to Obtain or Fulfill a Contract January 1, 2018 (in thousands) Cash and cash equivalents $ 51,562 $ — $ — $ — $ — $ 51,562 Short-term investments 39,178 — — — — 39,178 Accounts receivable, net 73,661 — — — — 73,661 Deferred contract acquisition and fulfillment costs, current portion — — — — 7,844 7,844 Prepaid expenses and other current assets 8,877 — 30 — — 8,907 Long-term investments 1,102 — — — — 1,102 Property and equipment, net 8,589 — — — — 8,589 Goodwill 83,164 — — — — 83,164 Intangible assets, net 16,640 — — — — 16,640 Deferred contract acquisition and fulfillment costs, non-current portion — — — — 19,321 19,321 Other assets 1,363 — — — — 1,363 Total assets $ 284,136 $ — $ 30 $ — $ 27,165 $ 311,331 Accounts payable $ 2,240 $ — $ — $ — $ — $ 2,240 Accrued expenses 29,728 — — — — 29,728 Deferred revenue, current portion 155,811 (10,912 ) (1,523 ) (1,356 ) — 142,020 Other current liabilities 1,706 — — — — 1,706 Deferred revenue, non-current portion 68,689 17,647 (2,624 ) (339 ) — 83,373 Other long-term liabilities 1,809 — — — 429 2,238 Total liabilities 259,983 6,735 (4,147 ) (1,695 ) 429 261,305 Common stock 441 — — — — 441 Treasury stock (4,764 ) — — — — (4,764 ) Additional paid-in-capital 463,428 — — — — 463,428 Accumulated other comprehensive loss (39 ) — — — — (39 ) Accumulated deficit (434,913 ) (6,735 ) 4,177 1,695 26,736 (409,040 ) Total stockholders’ equity 24,153 (6,735 ) 4,177 1,695 26,736 50,026 Total liabilities and stockholders’ equity $ 284,136 $ — $ 30 $ — $ 27,165 $ 311,331 Term and Perpetual Licenses Prior to the adoption of ASC 606, we recognized revenue for our term and perpetual licenses over the contractual period of maintenance and support due to the lack of vendor-specific objective evidence of selling price of maintenance and support. Under ASC 606, for our term and perpetual licenses which are not dependent on the continued delivery of content subscriptions, revenue is recognized at the time of delivery. For our perpetual licenses where the utility to the customer is dependent on the continued delivery of content subscriptions, the content subscription renewal option results in a material right with respect to the perpetual license. As a result, revenue related to the sale of these perpetual licenses is recognized ratably over the customer's estimated economic life of five years. The net impact of these changes resulted in a $6.7 million adjustment to accumulated deficit with an associated increase to deferred revenue. Professional Services Under ASC 605, professional services that were sold with term or perpetual licenses were recognized ratably over the contractual period of maintenance and support. Under ASC 606, these services are deemed distinct performance obligations and therefore recognized as the services are performed. The net impact of these changes resulted in a $4.2 million adjustment to accumulated deficit with an associated decrease to deferred revenue. Costs to Obtain or Fulfill a Contract Prior to the adoption of ASC 606, we expensed sales commissions in the period that they were earned by our employees (which was typically upon signing of an arrangement). Under ASC 606, the direct and incremental costs to obtain contracts with customers, including sales commissions, are deferred and recognized over a period of benefit that we have determined to be five years. In addition, under ASC 606, contract fulfillment costs associated with certain of our product offerings are deferred and amortized over the estimated period of benefit. Prior to the adoption of ASC 606, such costs were expensed as incurred. The net impact of these changes resulted in a $27.2 million increase in deferred contract acquisition and fulfillment costs and an adjustment to accumulated deficit. Income Taxes Deferred tax liabilities increased by $0.4 million due to the net impact of temporary differences associated with deferred revenue and capitalized costs to obtain or fulfill a contract created as a result of the adoption of ASC 606. As we fully reserve our net deferred tax assets in the United States, the United Kingdom and Ireland, the majority of the impact was offset by a corresponding adjustment to our valuation allowance. Accounting Pronouncements Not Yet Effective In August 2018, the FASB issued ASU 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, which aligns the requirements for capitalizing implementation costs in cloud computing arrangements with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. The new standard will be effective for us in the first quarter of 2020, with early adoption permitted. Entities can choose to adopt the new guidance prospectively or retrospectively. We are currently in the process of evaluating the effects of this pronouncement on our consolidated financial statements. In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement, which eliminates, modifies and adds disclosure requirements for fair value measurements. The new standard will be effective for us in the first quarter of 2020, with early adoption permitted. This ASU is not expected to have an impact on our consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases , which was further clarified by ASU 2018-10, Codification Improvements to Topic 842, Leases , and ASU 2018-11, Leases (Topic 842): Targeted Improvements , both issued in July 2018. ASU 2016-02 requires companies to recognize on the balance sheet the assets and liabilities for the rights and obligations created by leased assets. The new standard also will require additional disclosure of qualitative and quantitative information about the amounts recorded in the financial statements related to lease agreements. The new standard will be effective for us in the first quarter of 2019. The standard requires a transition adoption election using either (1) a modified retrospective approach with periods prior to the adoption date being restated or 2) a prospective adoption approach with a cumulative-effect adjustment recognized to the opening balance of retained earnings on the adoption date with prior periods not restated. We are currently evaluating the impact that the adoption of this standard will have on our consolidated financial statements. We plan to adopt this standard using the prospective adoption approach and electing the practical expedients allowed under the standard. Although we have not finalized our evaluation of the impact of adoption of the standard on our consolidated financial statements, we expect there will be a material increase to assets and liabilities related to the recognition of new right-of-use assets and lease liabilities on our balance sheet for leases currently classified as operating leases.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Disaggregation of Revenue	The following table summarizes revenue from contracts with customers for the year ended December 31, 2018 : Year Ended (in thousands) Subscription revenue $ 137,442 Term and perpetual software licenses 28,200 Maintenance and support 42,223 Professional services 33,297 Other 2,929 Total revenue $ 244,091 The following table summarizes the revenue by region based on the shipping address of customers who have contracted to use our product or service for the year ended December 31, 2018 : Year Ended (in thousands) United States $ 199,852 All other 44,239 Total revenue $ 244,091
Capitalized Contract Cost	The following table summarizes the activity of the deferred contract acquisition and fulfillment costs for the year ended December 31, 2018 : Year Ended (in thousands) Beginning balance $ 27,165 Capitalization of contract acquisition and fulfillment costs 22,765 Amortization of deferred contract acquisition and fulfillment costs (9,975 ) Ending balance $ 39,955
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction	The following table includes estimated revenue expected to be recognized in the future related to performance obligations that are unsatisfied or partially unsatisfied as of December 31, 2018 . The estimated revenues do not include unexercised contract renewals. 2019 2020 2021 and thereafter (in thousands) Subscription revenue $ 129,539 $ 37,471 $ 980 Term and perpetual software licenses 22,880 20,776 4,043 Maintenance and support 26,966 6,536 110
Schedule of Allowance for Doubtful Accounts	The following table displays the changes in our allowance for doubtful accounts: Amount (in thousands) Balance at December 31, 2015 $ 730 Additions, net of recoveries 931 Less write-offs (600 ) Balance at December 31, 2016 1,061 Additions, net of recoveries 905 Less write-offs (488 ) Balance at December 31, 2017 1,478 Additions, net of recoveries 740 Less write-offs (594 ) Balance at December 31, 2018 $ 1,624
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	Year Ended December 31, 2018 Statement of Operations As Reported under ASC 606 Proforma as if ASC 605 was in effect (in thousands, except share and per share data) Revenue: Products $ 168,571 175,146 Maintenance and support 42,223 45,767 Professional services 33,297 35,010 Total revenue 244,091 255,923 Cost of revenue: Products 39,810 39,761 Maintenance and support 7,678 7,678 Professional services 23,595 23,577 Total cost of revenue 71,083 71,016 Total gross profit 173,008 184,907 Operating expenses: Research and development 67,743 67,743 Sales and marketing 123,310 136,167 General and administrative 34,993 34,993 Total operating expenses 226,046 238,903 Loss from operations (53,038 ) (53,996 ) Other income (expense), net: Interest income 3,229 3,229 Interest expense (4,934 ) (4,934 ) Other income (expense), net (336 ) (336 ) Loss before income taxes (55,079 ) (56,037 ) Provision for income taxes 466 157 Net loss $ (55,545 ) $ (56,194 ) Net loss per share, basic and diluted $ (1.20 ) $ (1.21 ) Weighted-average common shares outstanding, basic and diluted 46,456,825 46,456,825 The following tables summarize the impact as of and for the year ended December 31, 2018 : As of December 31, 2018 Balance Sheet As Reported under ASC 606 Proforma as if ASC 605 was in effect (in thousands) Cash and cash equivalents $ 99,565 $ 99,565 Short-term investments 159,210 159,210 Accounts receivable, net 74,935 74,935 Deferred contract acquisition and fulfillment costs, current portion 12,321 — Prepaid expenses and other current assets 9,746 9,281 Long-term investments 44,892 44,892 Property and equipment, net 17,523 17,523 Goodwill 88,420 88,420 Intangible assets, net 23,955 23,955 Deferred contract acquisition and fulfillment costs, non-current portion 27,634 — Other assets 1,168 1,168 Total assets $ 559,369 $ 518,949 Accounts payable 7,048 7,048 Accrued expenses 37,376 37,376 Deferred revenue, current portion 189,855 193,763 Other current liabilities 707 707 Convertible senior notes, net 174,688 174,688 Deferred revenue, non-current portion 58,716 41,658 Other long-term liabilities 3,660 2,912 Total liabilities 472,050 458,152 Common stock 476 476 Treasury stock (4,764 ) (4,764 ) Additional paid-in-capital 556,223 556,223 Accumulated other comprehensive loss (31 ) (31 ) Accumulated deficit (464,585 ) (491,107 ) Total stockholders’ equity 87,319 60,797 Total liabilities and stockholders’ equity $ 559,369 $ 518,949 Year Ended December 31, 2018 Statement of Cash Flows As Reported under ASC 606 Proforma as if ASC 605 was in effect (in thousands) Net loss $ (55,545 ) $ (56,194 ) Adjustments to reconcile net loss to net cash provided by operating activities 43,443 43,125 Changes in operating assets and liabilities: Accounts receivable (1,685 ) (1,685 ) Deferred contract acquisition and fulfillment costs (12,790 ) — Prepaid expenses and other assets (287 ) 146 Accounts payable 3,675 3,675 Accrued expenses 6,018 6,018 Deferred revenue 22,870 10,614 Other liabilities 367 367 Net cash provided by operating activities $ 6,066 $ 6,066 As a result of applying the modified retrospective method to adopt ASC 606, the following adjustments were made to the consolidated balance sheet as of January 1, 2018: As Reported Adjustments Adjusted under ASC 606 December 31, 2017 Term and Perpetual License Professional Services Other Costs to Obtain or Fulfill a Contract January 1, 2018 (in thousands) Cash and cash equivalents $ 51,562 $ — $ — $ — $ — $ 51,562 Short-term investments 39,178 — — — — 39,178 Accounts receivable, net 73,661 — — — — 73,661 Deferred contract acquisition and fulfillment costs, current portion — — — — 7,844 7,844 Prepaid expenses and other current assets 8,877 — 30 — — 8,907 Long-term investments 1,102 — — — — 1,102 Property and equipment, net 8,589 — — — — 8,589 Goodwill 83,164 — — — — 83,164 Intangible assets, net 16,640 — — — — 16,640 Deferred contract acquisition and fulfillment costs, non-current portion — — — — 19,321 19,321 Other assets 1,363 — — — — 1,363 Total assets $ 284,136 $ — $ 30 $ — $ 27,165 $ 311,331 Accounts payable $ 2,240 $ — $ — $ — $ — $ 2,240 Accrued expenses 29,728 — — — — 29,728 Deferred revenue, current portion 155,811 (10,912 ) (1,523 ) (1,356 ) — 142,020 Other current liabilities 1,706 — — — — 1,706 Deferred revenue, non-current portion 68,689 17,647 (2,624 ) (339 ) — 83,373 Other long-term liabilities 1,809 — — — 429 2,238 Total liabilities 259,983 6,735 (4,147 ) (1,695 ) 429 261,305 Common stock 441 — — — — 441 Treasury stock (4,764 ) — — — — (4,764 ) Additional paid-in-capital 463,428 — — — — 463,428 Accumulated other comprehensive loss (39 ) — — — — (39 ) Accumulated deficit (434,913 ) (6,735 ) 4,177 1,695 26,736 (409,040 ) Total stockholders’ equity 24,153 (6,735 ) 4,177 1,695 26,736 50,026 Total liabilities and stockholders’ equity $ 284,136 $ — $ 30 $ — $ 27,165 $ 311,331
Summary of Property and Equipment	The following table presents the useful lives of our property and equipment: Useful Lives Computer equipment and software 3 years Furniture and fixtures 5 - 7 years Leasehold improvements Shorter of the useful life of the asset or the lease term Property and equipment are recorded at cost and consist of the following: As of December 31, 2018 2017 (in thousands) Computer equipment and software $ 18,724 $ 16,205 Furniture and fixtures 5,580 4,034 Leasehold improvements (1) 19,437 9,079 Total 43,741 29,318 Less accumulated depreciation (26,218 ) (20,729 ) Property and equipment, net $ 17,523 $ 8,589 (1) As of December 31, 2018, leasehold improvements included $4.0 million of construction-in progress related to our new Boston, Massachusetts corporate headquarters facility.

Business Combinations (Tables)

Business Combinations (Tables)	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Schedule of Preliminary Allocation of Purchase Price	The following table summarizes the cash consideration paid for tCell and the preliminary allocation of purchase price to the estimated fair value of the assets acquired and liabilities assumed at the acquisition date (in thousands): Cash consideration $ 15,414 Recognized amount of identifiable assets acquired and liabilities assumed: Cash and cash equivalents 1,089 Other net working capital (91 ) Intangible asset 9,160 Total identifiable net assets assumed 10,158 Goodwill 5,256 Total purchase price allocation $ 15,414
Schedule of Fair Value of Finite-Lived Intangible Assets Acquired	The fair value of the identifiable intangible asset was based on a valuation using a cost approach. The estimated fair value and useful life of the identifiable intangible asset was as follows: Amount Weighted Average Amortization Life (years) (in thousands) Developed technology $ 9,160 5

Fair Value Measurements and I_2

Fair Value Measurements and Investments (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Summary of Financial Assets and Liabilities Measured and Recorded at Fair Value on Recurring Basis	The following table presents our financial assets measured and recorded at fair value on a recurring basis using the above input categories: As of December 31, 2018 Level 1 Level 2 Level 3 Total (in thousands) Description: Assets: Money market funds $ 55,646 $ — $ — $ 55,646 U.S. Government agencies 74,481 — — 74,481 Commercial paper — 57,554 — 57,554 Corporate bonds — 48,495 — 48,495 Agency bonds 19,087 19,087 Asset-backed securities — 7,483 — 7,483 Total assets $ 130,127 $ 132,619 $ — $ 262,746 As of December 31, 2017 Level 1 Level 2 Level 3 Total (in thousands) Description: Assets: Money market funds $ 95 $ — $ — $ 95 U.S. Government agencies 11,869 — — 11,869 Commercial paper — 12,942 — 12,942 Corporate bonds — 12,964 — 12,964 Asset-backed securities — 2,505 — 2,505 Total assets $ 11,964 $ 28,411 $ — $ 40,375
Summary of Investments Classified as Available-for-sale	Our investments, which are all classified as available-for-sale, consisted of the following: As of December 31, 2018 Amortized Gross Gross Fair Value (in thousands) Description: U.S. Government agencies $ 71,480 $ 20 $ (17 ) $ 71,483 Commercial paper 57,554 — — 57,554 Corporate bonds 48,532 15 (52 ) 48,495 Agency bonds 19,077 16 (6 ) 19,087 Asset-backed securities 7,490 — (7 ) 7,483 Total $ 204,133 $ 51 $ (82 ) $ 204,102 As of December 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) Description: U.S. Government agencies $ 11,880 $ — $ (11 ) $ 11,869 Commercial paper 12,942 — — 12,942 Corporate bonds 12,991 — (27 ) 12,964 Asset-backed securities 2,506 — (1 ) 2,505 Total $ 40,319 $ — $ (39 ) $ 40,280

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Summary of Property and Equipment	The following table presents the useful lives of our property and equipment: Useful Lives Computer equipment and software 3 years Furniture and fixtures 5 - 7 years Leasehold improvements Shorter of the useful life of the asset or the lease term Property and equipment are recorded at cost and consist of the following: As of December 31, 2018 2017 (in thousands) Computer equipment and software $ 18,724 $ 16,205 Furniture and fixtures 5,580 4,034 Leasehold improvements (1) 19,437 9,079 Total 43,741 29,318 Less accumulated depreciation (26,218 ) (20,729 ) Property and equipment, net $ 17,523 $ 8,589 (1) As of December 31, 2018, leasehold improvements included $4.0 million of construction-in progress related to our new Boston, Massachusetts corporate headquarters facility.

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Changes in Gross Carrying Amount of Goodwill	The following table displays the changes in the gross carrying amount of goodwill: Amount (in thousands) Balance at December 31, 2016 $ 75,110 Komand acquisition 8,054 Balance at December 31, 2017 $ 83,164 tCell acquisition 5,256 Balance at December 31, 2018 $ 88,420
Schedule of Identifiable Intangible Assets	The following table presents details of our intangible assets which include acquired identifiable intangible assets and capitalized internal-use software costs: As of December 31, 2018 As of December 31, 2017 Weighted- Gross Carrying Accumulated Net Book Value Gross Carrying Accumulated Net Book Value (in thousands) Intangible assets subject to amortization: Developed technology 5.5 $ 29,771 $ (9,741 ) $ 20,030 $ 20,611 $ (5,756 ) $ 14,855 Customer relationships 6.7 1,000 (504 ) 496 1,000 (351 ) 649 Trade names 6.1 519 (516 ) 3 519 (510 ) 9 Non-compete agreements 2.0 40 (40 ) — 40 (40 ) — Total acquired intangible assets 31,330 (10,801 ) 20,529 22,170 (6,657 ) 15,513 Internal-use software 3,786 (360 ) 3,426 1,162 (35 ) 1,127 Total intangible assets $ 35,116 $ (11,161 ) $ 23,955 $ 23,332 $ (6,692 ) $ 16,640
Schedule of Estimated Amortization Expense	Estimated future amortization expense of the acquired identifiable intangible assets and completed capitalized internal-use software costs as of December 31, 2018 is as follows (in thousands): 2019 $ 6,251 2020 6,193 2021 5,398 2022 2,927 2023 1,451 2024 and thereafter — Total $ 22,220

Convertible Senior Notes and _2

Convertible Senior Notes and Capped Calls (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Schedule of Liability and Equity Components of Convertible Debt	The net carrying amount of the liability component of the Notes was as follows: As of (in thousands) Principal $ 230,000 Unamortized debt discount (50,334 ) Unamortized issuance costs (4,978 ) Net carrying amount $ 174,688 The net carrying amount of the equity component was as follows: As of (in thousands) Debt discount for conversion option $ 53,820 Issuance costs (1,626 ) Net carrying amount $ 52,194 Interest expense related to the Notes was as follows: Year Ended December 31, 2018 (in thousands) Contractual interest expense $ 1,103 Amortization of debt discount 3,486 Amortization of issuance costs 345 Total interest expense $ 4,934 The net impact to our stockholders' equity, included in additional paid-in capital, of the above components of the Notes was as follows (in thousands): Conversion option $ 53,820 Purchase of capped calls (26,910 ) Issuance costs (1,626 ) Total $ 25,284
Schedule of Interest Payments on Debt Instruments	The future payments of the principal and contractual interest related to the Notes as of December 31, 2018 are as follows (in thousands): Principal Interest Total 2019 $ — $ 2,779 $ 2,779 2020 — 2,875 2,875 2021 — 2,875 2,875 2022 — 2,875 2,875 2023 230,000 2,875 232,875 Total $ 230,000 $ 14,279 $ 244,279

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Stock-Based Compensation Expense	Stock-based compensation expense for restricted stock, restricted stock units, stock options and issuances of common stock pursuant to our employee stock purchase plan was classified in the accompanying consolidated statements of operations as follows: Year Ended December 31, 2018 2017 2016 (in thousands) Stock-based compensation expense: Cost of revenue $ 1,692 $ 1,085 $ 610 Research and development 10,822 7,205 6,054 Sales and marketing 7,569 5,756 6,607 General and administrative 7,510 5,495 4,045 Total stock-based compensation expense $ 27,593 $ 19,541 $ 17,316
Summary of Restricted Stock and Restricted Stock Unit Activity	Restricted stock and restricted stock unit activity during 2018 , 2017 and 2016 was as follows: Restricted Stock Restricted Stock Units Shares Weighted- Shares Weighted- Unvested balance as of December 31, 2015 1,149,257 $ 19.34 — $ — Granted — — 919,397 13.37 Vested (538,896 ) 20.67 (91,020 ) 12.93 Forfeited (25,357 ) 20.96 (93,800 ) 12.97 Unvested balance as of December 31, 2016 585,004 18.05 734,577 13.47 Granted — — 1,938,860 14.97 Vested (358,214 ) 17.85 (435,573 ) 13.80 Forfeited (16,707 ) 23.01 (249,355 ) 14.22 Unvested balance as of December 31, 2017 210,083 18.00 1,988,509 14.77 Granted — — 2,099,394 25.19 Vested (187,706 ) 18.80 (973,443 ) 17.41 Forfeited (700 ) 23.01 (340,687 ) 18.96 Unvested balance as of December 31, 2018 21,677 $ 10.88 2,773,773 $ 21.21
Summary of Stock Option Activity	The following table summarizes information about stock option activity during the reporting periods: Shares Weighted Weighted Aggregate Outstanding as of December 31, 2015 4,246,525 $ 5.99 Granted 1,454,626 13.43 Options assumed from acquisition — — Exercised (650,185 ) 4.43 $ 6,409 Forfeited/cancelled (470,591 ) 9.65 Outstanding as of December 31, 2016 4,580,375 8.20 Granted 1,304,238 13.52 Exercised (887,062 ) 6.59 $ 9,665 Forfeited/cancelled (312,597 ) 12.79 Outstanding as of December 31, 2017 4,684,954 9.68 Granted 107,850 24.44 Exercised (944,658 ) 8.05 $ 19,982 Forfeited/cancelled (134,967 ) 15.20 Outstanding as of December 31, 2018 3,713,179 $ 10.32 6.20 $ 77,396 Vested and exercisable as of December 31, 2018 2,685,963 $ 8.76 5.55 $ 60,169
Summary of Share Based Compensation Valuation of Options Granted Assumptions	The following table reflects the range of assumptions for options granted during 2018 , 2017 and 2016 : Year Ended December 31, 2018 2017 2016 Expected term (in years) 6.1 5.5 - 6.1 5.5 – 6.3 Expected volatility 46 – 48% 48 – 52% 48 – 50% Risk-free interest rate 2.4 – 2.8% 1.8 – 2.2% 1.2 – 1.9% Expected dividend yield — — — Grant date fair value per share $ 10.55 – 13.11 $ 6.09 – 9.38 $ 5.53 – 8.35 The following table reflects the assumptions used in the Black-Scholes option pricing model to calculate the expense related to the ESPP: Year Ended December 31, 2018 2017 2016 Expected term (in years) 0.5 - 1.0 0.5 - 1.0 0.5 - 1.0 Expected volatility 37% 37 – 40% 42 – 49% Risk-free interest rate 2.0 – 2.6% 0.9 – 1.3% 0.5 – 0.7% Expected dividend yield — — — Grant date fair value per share $ 6.62 – 10.95 $ 4.01 – 5.35 $ 3.58 – 5.49

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Components of Loss Before Income Taxes	Loss before income taxes included in the consolidated statements of operations was as follows: Year Ended December 31, 2018 2017 2016 (in thousands) United States $ (39,754 ) $ (22,757 ) $ (41,466 ) Foreign (15,325 ) (24,949 ) (7,561 ) Loss before income taxes $ (55,079 ) $ (47,706 ) $ (49,027 )
Summary of Income Tax (Benefit) Expense	Income tax expense (benefit) included in the consolidated statements of operations was as follows: Year Ended December 31, 2018 2017 2016 (in thousands) Current: Federal $ 124 $ 333 $ 493 State and local 126 128 61 Foreign 228 163 (656 ) Total current (benefit) expense 478 624 (102 ) Deferred: Federal (285 ) (2,885 ) 98 State and local 16 8 13 Foreign 257 17 (36 ) Total deferred expense (12 ) (2,860 ) 75 Income tax expense (benefit) $ 466 $ (2,236 ) $ (27 )
Reconciliation of Income Taxes Computed at Federal Statutory Rate and Provision for Income Taxes	The reconciliation of income tax expense (benefit) to the amount computed at the federal statutory rate of 21% for the year ended December 31, 2018 and 34% for the years ended December 31, 2017 and 2016 was as follows: Year Ended December 31, 2018 2017 2016 Expected income tax 21.0 % 34.0 % 34.0 % State taxes, net of federal benefit (0.2 ) (0.2 ) (0.1 ) Permanent differences 0.2 (0.4 ) (0.4 ) Stock compensation 9.3 4.6 (1.0 ) Federal research and development credit 1.2 1.0 2.4 Foreign rate differential (1.1 ) (8.7 ) (3.0 ) Change in valuation allowance (32.8 ) (26.1 ) (31.9 ) Other 1.5 0.5 0.1 Total income tax expense (benefit) (0.9 )% 4.7 % 0.1 %
Components of Net Deferred Tax Assets and Liabilities	Net deferred tax assets and liabilities, as set forth in the table below, reflect the impact of temporary differences between the amounts of assets and liabilities recorded for financial statement purposes and such amounts measured in accordance with tax laws: As of December 31, 2018 2017 (in thousands) Deferred tax assets: Accruals and reserves $ 397 $ 636 Net operating loss carryforwards 55,457 36,778 Deferred revenue 15,421 11,985 Depreciation 1,542 926 Research and development credits 3,440 2,441 Stock-based compensation 4,851 3,702 Tax credits 932 657 Other 953 557 Total deferred tax assets 82,993 57,682 Deferred tax liabilities: Intangible assets (1,104 ) (616 ) Convertible senior notes (12,537 ) — Deferred contract acquisition and fulfillment costs (9,796 ) — Other (79 ) — Total deferred tax liabilities (23,516 ) (616 ) Less: Valuation allowance (60,130 ) (57,359 ) Net deferred tax liabilities $ (653 ) $ (293 )
Changes in Reserves for Unrecognized Income Tax Benefits	Amount (in thousands) Balance at December 31, 2016 $ 388 Decreases based on settlements with taxing authorities (343 ) Reductions based on lapse in statute of limitations (16 ) Balance at December 31, 2017 29 Reductions based on lapse in statute of limitations (17 ) Balance at December 31, 2018 $ 12

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Summary of Basic and Diluted Net Loss Per Share of Common Stock	The following table summarizes the computation of basic and diluted net loss per share of our common stock for 2018 , 2017 and 2016 : Year Ended December 31, 2018 2017 2016 (in thousands, except share and per share data) Numerator: Net loss $ (55,545 ) $ (45,470 ) $ (49,000 ) Denominator: Weighted-average common shares outstanding, basic and diluted 46,456,825 42,952,950 41,248,473 Net loss per share, basic and diluted $ (1.20 ) $ (1.06 ) $ (1.19 )
Anti-Dilutive Securities Excluded from Computation Diluted Weighted Average Shares Outstanding	The following potentially dilutive securities outstanding, prior to the use of the treasury stock method or if-converted method, have been excluded from the computation of diluted weighted-average shares outstanding for the respective periods below because they would have been anti-dilutive: Year Ended December 31, 2018 2017 2016 Options to purchase common stock 3,713,179 4,684,954 4,580,375 Unvested restricted stock 21,677 210,083 585,004 Unvested restricted stock units 2,773,773 1,988,509 734,577 Shares to be issued under ESPP 74,634 79,551 91,815 Total 6,583,263 6,963,097 5,991,771

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Summary of Future Minimum Operating Leases	The future minimum payments under non-cancellable operating leases as of December 31, 2018 are as follows: 2019 $ 9,899 2020 11,616 2021 10,933 2022 11,054 2023 11,136 Thereafter 53,648 Total $ 108,286

Segment Information and Infor_2

Segment Information and Information about Geographic Areas (Tables)	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Net Revenues of Customer by Geographic Area	Net revenues by geographic area presented based upon the location of the customer are as follows: Year Ended December 31, 2018 2017 2016 (in thousands) North America $ 207,727 $ 170,667 $ 134,988 Other 36,364 30,273 22,449 Total $ 244,091 $ 200,940 $ 157,437
Property and Equipment, Net By Geographic Area	Property and equipment, net by geographic area as of December 31, 2018 and 2017 is presented in the table below: As of December 31, 2018 2017 (in thousands) United States $ 16,311 $ 7,182 Other 1,212 1,407 Total $ 17,523 $ 8,589

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Aug. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018
Organization Consolidation And Presentation Of Financial Statements Disclosure And Significant Accounting Policies [Line Items]
Liability, revenue recognized		$ 135,600,000
Contract with customer, asset, net		800,000			$ 300,000
Reported assets		40,400,000
Reported deferred costs		40,000,000
Reported liabilities		13,900,000
Total revenue		244,091,000	$ 200,940,000	$ 157,437,000
Sales and marketing		(123,310,000)	(111,593,000)	(90,524,000)
Provision for (benefit from) income taxes		466,000	(2,236,000)	(27,000)
Cash and cash equivalents		99,565,000	51,562,000	53,148,000	51,562,000
Restricted cash in other assets		0	200,000	0
Capitalized computer software, additions		3,300,000	1,200,000	$ 0
Unamortized capitalized costs relating to software acquired for internal use		$ 3,400,000	$ 1,100,000
Antidilutive securities excluded from computation of earnings per share amount		6,583,263	6,963,097	5,991,771
Accumulated deficit		$ (464,585,000)	$ (434,913,000)		(409,040,000)
Deferred tax liabilities, net		$ 653,000	293,000
Convertible Debt Securities [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure And Significant Accounting Policies [Line Items]
Antidilutive securities excluded from computation of earnings per share amount		5,500,000
The Notes [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure And Significant Accounting Policies [Line Items]
Strike price (in dollars per share)	$ 41.59
Nonoperating Income (Expense) [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure And Significant Accounting Policies [Line Items]
Foreign currency re-measurement (gain) losses		$ (800,000)	400,000	$ (100,000)
Sales and Marketing [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure And Significant Accounting Policies [Line Items]
Advertising costs		8,900,000	8,400,000	6,000,000
Money Market Funds [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure And Significant Accounting Policies [Line Items]
Cash and cash equivalents		58,600,000	100,000
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure And Significant Accounting Policies [Line Items]
Product revenue		(6,600,000)
Sales and marketing		12,900,000
Provision for (benefit from) income taxes		$ 300,000
Deferred costs					27,200,000
Deferred tax liabilities, net					400,000
Cloud-Based Subscription Contract [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure And Significant Accounting Policies [Line Items]
Contract term		1 year
Managed Services Offerings [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure And Significant Accounting Policies [Line Items]
Contract term		1 year
Term And Perpetual License [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure And Significant Accounting Policies [Line Items]
Total revenue		$ 28,200,000
Term And Perpetual License [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure And Significant Accounting Policies [Line Items]
Customer economic life		5 years
Term And Perpetual License [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure And Significant Accounting Policies [Line Items]
Cash and cash equivalents					0
Accumulated deficit					(6,735,000)
Deferred revenue					6,700,000
Professional Services [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure And Significant Accounting Policies [Line Items]
Total revenue		$ 33,297,000	37,924,000	30,630,000
Amortization period		1 year
Professional Services [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure And Significant Accounting Policies [Line Items]
Contractual period		1 year
Professional Services [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure And Significant Accounting Policies [Line Items]
Total revenue		$ (1,700,000)
Cash and cash equivalents					0
Accumulated deficit					4,177,000
Deferred revenue					$ 4,200,000
Maintenance and Support [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure And Significant Accounting Policies [Line Items]
Total revenue		$ 42,223,000
Maintenance and Support [Member] | Minimum [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure And Significant Accounting Policies [Line Items]
Contractual period		1 year
Maintenance and Support [Member] | Maximum [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure And Significant Accounting Policies [Line Items]
Contractual period		3 years
Maintenance [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure And Significant Accounting Policies [Line Items]
Total revenue		$ 42,223,000	$ 46,268,000	$ 37,403,000
Maintenance [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure And Significant Accounting Policies [Line Items]
Total revenue		$ (3,500,000)

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Total revenue	$ 244,091	$ 200,940	$ 157,437
United States [Member]
Disaggregation of Revenue [Line Items]
Total revenue	199,852
Non-US [Member]
Disaggregation of Revenue [Line Items]
Total revenue	44,239
Subscription Revenue [Member]
Disaggregation of Revenue [Line Items]
Total revenue	137,442
Term And Perpetual License [Member]
Disaggregation of Revenue [Line Items]
Total revenue	28,200
Maintenance and Support [Member]
Disaggregation of Revenue [Line Items]
Total revenue	42,223
Professional Services [Member]
Disaggregation of Revenue [Line Items]
Total revenue	33,297	$ 37,924	$ 30,630
Timing Of Transfer Of Good Or Service, Other [Member]
Disaggregation of Revenue [Line Items]
Total revenue	$ 2,929

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Remaining Performance Obligation (Details) $ in Thousands	Dec. 31, 2018USD ($)
Subscription Revenue [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, amount	$ 129,539
Subscription Revenue [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue recognition period	1 year
Remaining performance obligation, amount	$ 37,471
Subscription Revenue [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue recognition period	1 year
Remaining performance obligation, amount	$ 980
Subscription Revenue [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue recognition period
Term And Perpetual License [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, amount	$ 22,880
Term And Perpetual License [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue recognition period	1 year
Remaining performance obligation, amount	$ 20,776
Term And Perpetual License [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue recognition period	1 year
Remaining performance obligation, amount	$ 4,043
Term And Perpetual License [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue recognition period
Maintenance and Support [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, amount	$ 26,966
Maintenance and Support [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue recognition period	1 year
Remaining performance obligation, amount	$ 6,536
Maintenance and Support [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue recognition period	1 year
Remaining performance obligation, amount	$ 110
Maintenance and Support [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue recognition period
Professional Services [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue recognition period	12 months
Remaining performance obligation, amount	$ 12,000

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cash and cash equivalents	$ 99,565	$ 51,562	$ 51,562	$ 53,148
Short-term investments	159,210	39,178	39,178
Accounts receivable, net of allowance for doubtful accounts of $1,624 and $1,478 at December 31, 2018 and 2017, respectively	74,935	73,661	73,661
Deferred contract acquisition and fulfillment costs, current portion	12,321	7,844	0
Prepaid expenses and other current assets	9,746	8,907	8,877
Long-term investments	44,892	1,102	1,102
Property and equipment, net	17,523	8,589	8,589
Goodwill	88,420	83,164	83,164	75,110
Intangible assets, net	23,955	16,640	16,640
Deferred contract acquisition and fulfillment costs, non-current portion	27,634	19,321	0
Other assets	1,168	1,363	1,363
Total assets	559,369	311,331	284,136
Accounts payable	7,048	2,240	2,240
Accrued expenses	37,376	29,728	29,728
Deferred revenue, current portion	189,855	142,020	155,811
Other current liabilities	707	1,706	1,706
Convertible senior notes, net	174,688		0
Deferred revenue, non-current portion	58,716	83,373	68,689
Other long-term liabilities	3,660	2,238	1,809
Total liabilities	472,050	261,305	259,983
Common stock, $0.01 par value per share; 100,000,000 shares authorized at December 31, 2018 and 2017; 48,087,257 and 44,540,544 shares issued at December 31, 2018 and 2017, respectively; 47,600,449 and 44,053,736 shares outstanding at December 31, 2018 and 2017, respectively	476	441	441
Treasury stock	(4,764)	(4,764)	(4,764)
Additional paid-in-capital	556,223	463,428	463,428
Accumulated other comprehensive loss	(31)	(39)	(39)
Accumulated deficit	(464,585)	(409,040)	(434,913)
Total stockholders’ equity	87,319	50,026	24,153	$ 42,038	$ 68,075
Total liabilities and stockholders’ equity	559,369	$ 311,331	284,136
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cash and cash equivalents	99,565		51,562
Short-term investments	159,210		39,178
Accounts receivable, net of allowance for doubtful accounts of $1,624 and $1,478 at December 31, 2018 and 2017, respectively	74,935		73,661
Deferred contract acquisition and fulfillment costs, current portion	0		0
Prepaid expenses and other current assets	9,281		8,877
Long-term investments	44,892		1,102
Property and equipment, net	17,523		8,589
Goodwill	88,420		83,164
Intangible assets, net	23,955		16,640
Deferred contract acquisition and fulfillment costs, non-current portion	0		0
Other assets	1,168		1,363
Total assets	518,949		284,136
Accounts payable	7,048		2,240
Accrued expenses	37,376		29,728
Deferred revenue, current portion	193,763		155,811
Other current liabilities	707		1,706
Convertible senior notes, net	174,688
Deferred revenue, non-current portion	41,658		68,689
Other long-term liabilities	2,912		1,809
Total liabilities	458,152		259,983
Common stock, $0.01 par value per share; 100,000,000 shares authorized at December 31, 2018 and 2017; 48,087,257 and 44,540,544 shares issued at December 31, 2018 and 2017, respectively; 47,600,449 and 44,053,736 shares outstanding at December 31, 2018 and 2017, respectively	476		441
Treasury stock	(4,764)		(4,764)
Additional paid-in-capital	556,223		463,428
Accumulated other comprehensive loss	(31)		(39)
Accumulated deficit	(491,107)		(434,913)
Total stockholders’ equity	60,797		24,153
Total liabilities and stockholders’ equity	$ 518,949		$ 284,136

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Statement of Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue:
Total revenue	$ 244,091	$ 200,940	$ 157,437
Cost of revenue:
Total cost of revenue	71,083	56,910	39,725
Total gross profit	173,008	144,030	117,712
Operating expenses:
Research and development	67,743	50,938	47,955
Sales and marketing	123,310	111,593	90,524
General and administrative	34,993	30,293	28,282
Total operating expenses	226,046	192,824	166,761
Loss from operations	(53,038)	(48,794)	(49,049)
Other income (expense), net:
Interest income	3,229	862	342
Interest expense	(4,934)	(87)	(211)
Other income (expense), net	(336)	313	(109)
Loss before income taxes	(55,079)	(47,706)	(49,027)
Provision for (benefit from) income taxes	466	(2,236)	(27)
Net loss	$ (55,545)	$ (45,470)	$ (49,000)
Net loss per share, basic and diluted (in dollars per share)	$ (1.20)	$ (1.06)	$ (1.19)
Weighted-average common shares outstanding, basic and diluted (in shares)	46,456,825	42,952,950	41,248,473
Product [Member]
Revenue:
Total revenue	$ 168,571	$ 116,748	$ 89,404
Cost of revenue:
Total cost of revenue	39,810	25,583	12,447
Maintenance [Member]
Revenue:
Total revenue	42,223	46,268	37,403
Cost of revenue:
Total cost of revenue	7,678	7,491	7,105
Professional Services [Member]
Revenue:
Total revenue	33,297	37,924	30,630
Cost of revenue:
Total cost of revenue	23,595	$ 23,836	$ 20,173
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Revenue:
Total revenue	255,923
Cost of revenue:
Total cost of revenue	71,016
Total gross profit	184,907
Operating expenses:
Research and development	67,743
Sales and marketing	136,167
General and administrative	34,993
Total operating expenses	238,903
Loss from operations	(53,996)
Other income (expense), net:
Interest income	3,229
Interest expense	(4,934)
Other income (expense), net	(336)
Loss before income taxes	(56,037)
Provision for (benefit from) income taxes	157
Net loss	$ (56,194)
Net loss per share, basic and diluted (in dollars per share)	$ (1.21)
Weighted-average common shares outstanding, basic and diluted (in shares)	46,456,825
Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Product [Member]
Revenue:
Total revenue	$ 175,146
Cost of revenue:
Total cost of revenue	39,761
Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Maintenance [Member]
Revenue:
Total revenue	45,767
Cost of revenue:
Total cost of revenue	7,678
Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Professional Services [Member]
Revenue:
Total revenue	35,010
Cost of revenue:
Total cost of revenue	$ 23,577

Summary of Significant Accoun_9

Summary of Significant Accounting Policies - Statement of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net loss	$ (55,545)	$ (45,470)	$ (49,000)
Adjustments to reconcile net loss to net cash provided by operating activities	43,443
Changes in assets and liabilities:
Accounts receivable	(1,685)	(25,217)	(6,195)
Deferred contract acquisition and fulfillment costs	(12,790)	0	0
Prepaid expenses and other assets	(287)	(74)	(3,523)
Accounts payable	3,675	(2,257)	1,619
Accrued expenses	6,018	6,758	1,578
Deferred revenue	22,870	55,437	38,748
Other liabilities	367	(950)	558
Net cash provided by operating activities	6,066	$ 13,286	$ 9,112
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net loss	(56,194)
Adjustments to reconcile net loss to net cash provided by operating activities	43,125
Changes in assets and liabilities:
Accounts receivable	(1,685)
Deferred contract acquisition and fulfillment costs	0
Prepaid expenses and other assets	146
Accounts payable	3,675
Accrued expenses	6,018
Deferred revenue	10,614
Other liabilities	367
Net cash provided by operating activities	$ 6,066

Summary of Significant Accou_10

Summary of Significant Accounting Policies - Schedule of Allowance for Doubtful Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Allowance for Doubtful Accounts Receivable [Roll Forward]
Beginning Balance	$ 1,478	$ 1,061	$ 730
Additions, net of recoveries	740	905	931
Less write-offs	(594)	(488)	(600)
Ending Balance	$ 1,624	$ 1,478	$ 1,061

Summary of Significant Accou_11

Summary of Significant Accounting Policies - Useful Lives (Details)	12 Months Ended
	Dec. 31, 2018
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Useful life	3 years
Minimum [Member] | Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Useful life	5 years
Maximum [Member] | Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Useful life	7 years

Summary of Significant Accou_12

Summary of Significant Accounting Policies - Deferred Contract Acquisition and Fulfillment Costs (Details) - Contract Acquisition And Fulfillment Costs [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)
Capitalized Contract Cost [Roll Forward]
Beginning balance	$ 27,165
Capitalization of contract acquisition and fulfillment costs	22,765
Amortization of deferred contract acquisition and fulfillment costs	(9,975)
Ending balance	$ 39,955

Summary of Significant Accou_13

Summary of Significant Accounting Policies - Effect of ASC 606 (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cash and cash equivalents	$ 99,565	$ 51,562	$ 51,562	$ 53,148
Short-term investments	159,210	39,178	39,178
Accounts receivable, net of allowance for doubtful accounts of $1,624 and $1,478 at December 31, 2018 and 2017, respectively	74,935	73,661	73,661
Deferred contract acquisition and fulfillment costs, current portion	12,321	7,844	0
Prepaid expenses and other current assets	9,746	8,907	8,877
Long-term investments	44,892	1,102	1,102
Property and equipment, net	17,523	8,589	8,589
Goodwill	88,420	83,164	83,164	75,110
Intangible assets, net	23,955	16,640	16,640
Deferred contract acquisition and fulfillment costs, non-current portion	27,634	19,321	0
Other assets	1,168	1,363	1,363
Total assets	559,369	311,331	284,136
Accounts payable	7,048	2,240	2,240
Accrued expenses	37,376	29,728	29,728
Deferred revenue, current portion	189,855	142,020	155,811
Other current liabilities	707	1,706	1,706
Deferred revenue, non-current portion	58,716	83,373	68,689
Other long-term liabilities	3,660	2,238	1,809
Total liabilities	472,050	261,305	259,983
Common stock, $0.01 par value per share; 100,000,000 shares authorized at December 31, 2018 and 2017; 48,087,257 and 44,540,544 shares issued at December 31, 2018 and 2017, respectively; 47,600,449 and 44,053,736 shares outstanding at December 31, 2018 and 2017, respectively	476	441	441
Treasury stock	(4,764)	(4,764)	(4,764)
Additional paid-in-capital	556,223	463,428	463,428
Accumulated other comprehensive loss	(31)	(39)	(39)
Accumulated deficit	(464,585)	(409,040)	(434,913)
Total stockholders’ equity	87,319	50,026	24,153	$ 42,038	$ 68,075
Total liabilities and stockholders’ equity	559,369	311,331	284,136
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cash and cash equivalents	99,565		51,562
Short-term investments	159,210		39,178
Accounts receivable, net of allowance for doubtful accounts of $1,624 and $1,478 at December 31, 2018 and 2017, respectively	74,935		73,661
Deferred contract acquisition and fulfillment costs, current portion	0		0
Prepaid expenses and other current assets	9,281		8,877
Long-term investments	44,892		1,102
Property and equipment, net	17,523		8,589
Goodwill	88,420		83,164
Intangible assets, net	23,955		16,640
Deferred contract acquisition and fulfillment costs, non-current portion	0		0
Other assets	1,168		1,363
Total assets	518,949		284,136
Accounts payable	7,048		2,240
Accrued expenses	37,376		29,728
Deferred revenue, current portion	193,763		155,811
Other current liabilities	707		1,706
Deferred revenue, non-current portion	41,658		68,689
Other long-term liabilities	2,912		1,809
Total liabilities	458,152		259,983
Common stock, $0.01 par value per share; 100,000,000 shares authorized at December 31, 2018 and 2017; 48,087,257 and 44,540,544 shares issued at December 31, 2018 and 2017, respectively; 47,600,449 and 44,053,736 shares outstanding at December 31, 2018 and 2017, respectively	476		441
Treasury stock	(4,764)		(4,764)
Additional paid-in-capital	556,223		463,428
Accumulated other comprehensive loss	(31)		(39)
Accumulated deficit	(491,107)		(434,913)
Total stockholders’ equity	60,797		24,153
Total liabilities and stockholders’ equity	$ 518,949		$ 284,136
Term And Perpetual License [Member] | Accounting Standards Update 2014-09 [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cash and cash equivalents		0
Short-term investments		0
Accounts receivable, net of allowance for doubtful accounts of $1,624 and $1,478 at December 31, 2018 and 2017, respectively		0
Deferred contract acquisition and fulfillment costs, current portion		0
Prepaid expenses and other current assets		0
Long-term investments		0
Property and equipment, net		0
Goodwill		0
Intangible assets, net		0
Deferred contract acquisition and fulfillment costs, non-current portion		0
Other assets		0
Total assets		0
Accounts payable		0
Accrued expenses		0
Deferred revenue, current portion		(10,912)
Other current liabilities		0
Deferred revenue, non-current portion		17,647
Other long-term liabilities		0
Total liabilities		6,735
Common stock, $0.01 par value per share; 100,000,000 shares authorized at December 31, 2018 and 2017; 48,087,257 and 44,540,544 shares issued at December 31, 2018 and 2017, respectively; 47,600,449 and 44,053,736 shares outstanding at December 31, 2018 and 2017, respectively		0
Treasury stock		0
Additional paid-in-capital		0
Accumulated other comprehensive loss		0
Accumulated deficit		(6,735)
Total stockholders’ equity		(6,735)
Total liabilities and stockholders’ equity		0
Professional Services [Member] | Accounting Standards Update 2014-09 [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cash and cash equivalents		0
Short-term investments		0
Accounts receivable, net of allowance for doubtful accounts of $1,624 and $1,478 at December 31, 2018 and 2017, respectively		0
Deferred contract acquisition and fulfillment costs, current portion		0
Prepaid expenses and other current assets		30
Long-term investments		0
Property and equipment, net		0
Goodwill		0
Intangible assets, net		0
Deferred contract acquisition and fulfillment costs, non-current portion		0
Other assets		0
Total assets		30
Accounts payable		0
Accrued expenses		0
Deferred revenue, current portion		(1,523)
Other current liabilities		0
Deferred revenue, non-current portion		(2,624)
Other long-term liabilities		0
Total liabilities		(4,147)
Common stock, $0.01 par value per share; 100,000,000 shares authorized at December 31, 2018 and 2017; 48,087,257 and 44,540,544 shares issued at December 31, 2018 and 2017, respectively; 47,600,449 and 44,053,736 shares outstanding at December 31, 2018 and 2017, respectively		0
Treasury stock		0
Additional paid-in-capital		0
Accumulated other comprehensive loss		0
Accumulated deficit		4,177
Total stockholders’ equity		4,177
Total liabilities and stockholders’ equity		30
Timing Of Transfer Of Good Or Service, Other [Member] | Accounting Standards Update 2014-09 [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cash and cash equivalents		0
Short-term investments		0
Accounts receivable, net of allowance for doubtful accounts of $1,624 and $1,478 at December 31, 2018 and 2017, respectively		0
Deferred contract acquisition and fulfillment costs, current portion		0
Prepaid expenses and other current assets		0
Long-term investments		0
Property and equipment, net		0
Goodwill		0
Intangible assets, net		0
Deferred contract acquisition and fulfillment costs, non-current portion		0
Other assets		0
Total assets		0
Accounts payable		0
Accrued expenses		0
Deferred revenue, current portion		(1,356)
Other current liabilities		0
Deferred revenue, non-current portion		(339)
Other long-term liabilities		0
Total liabilities		(1,695)
Common stock, $0.01 par value per share; 100,000,000 shares authorized at December 31, 2018 and 2017; 48,087,257 and 44,540,544 shares issued at December 31, 2018 and 2017, respectively; 47,600,449 and 44,053,736 shares outstanding at December 31, 2018 and 2017, respectively		0
Treasury stock		0
Additional paid-in-capital		0
Accumulated other comprehensive loss		0
Accumulated deficit		1,695
Total stockholders’ equity		1,695
Total liabilities and stockholders’ equity		0
Costs To Obtain Or Fulfill A Contract [Member] | Accounting Standards Update 2014-09 [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cash and cash equivalents		0
Short-term investments		0
Accounts receivable, net of allowance for doubtful accounts of $1,624 and $1,478 at December 31, 2018 and 2017, respectively		0
Deferred contract acquisition and fulfillment costs, current portion		7,844
Prepaid expenses and other current assets		0
Long-term investments		0
Property and equipment, net		0
Goodwill		0
Intangible assets, net		0
Deferred contract acquisition and fulfillment costs, non-current portion		19,321
Other assets		0
Total assets		27,165
Accounts payable		0
Accrued expenses		0
Deferred revenue, current portion		0
Other current liabilities		0
Deferred revenue, non-current portion		0
Other long-term liabilities		429
Total liabilities		429
Common stock, $0.01 par value per share; 100,000,000 shares authorized at December 31, 2018 and 2017; 48,087,257 and 44,540,544 shares issued at December 31, 2018 and 2017, respectively; 47,600,449 and 44,053,736 shares outstanding at December 31, 2018 and 2017, respectively		0
Treasury stock		0
Additional paid-in-capital		0
Accumulated other comprehensive loss		0
Accumulated deficit		26,736
Total stockholders’ equity		26,736
Total liabilities and stockholders’ equity		$ 27,165

Business Combinations - Additio

Business Combinations - Additional Information (Detail)	Oct. 15, 2018USD ($)shares	Jul. 12, 2017USD ($)shares	Dec. 31, 2018USD ($)reporting_unitshares	Dec. 31, 2017USD ($)shares	Dec. 31, 2016USD ($)shares	Jan. 01, 2018USD ($)
Business Acquisition [Line Items]
Reporting unit | reporting_unit			1
Vesting period			4 years
Business acquisitions, net of cash acquired			$ 14,460,000	$ 14,717,000	$ 0
Goodwill			$ 88,420,000	$ 83,164,000	$ 75,110,000	$ 83,164,000
Restricted Stock Units [Member]
Business Acquisition [Line Items]
Equity instruments granted (in shares) | shares			2,099,394	1,938,860	919,397
tCell.io, Inc. [Member]
Business Acquisition [Line Items]
Cash consideration	$ 15,414,000
Acquisition related costs	100,000
Goodwill	5,256,000
Intangible asset	$ 9,160,000
tCell.io, Inc. [Member] | Restricted Stock Units [Member]
Business Acquisition [Line Items]
Equity instruments granted (in shares) | shares	112,924
Vesting period	3 years
Komand, Inc. [Member]
Business Acquisition [Line Items]
Acquisition related costs		$ 200,000
Reporting unit | reporting_unit			1
Percentage of shares outstanding acquired		100.00%
Business acquisitions, net of cash acquired		$ 14,700,000
Cash acquired from acquisition		100,000
Goodwill		8,100,000
Intangible asset		9,400,000
Release of valuation allowance		(2,600,000)
Contingent consideration, up to		$ 5,000,000
Komand, Inc. [Member] | Restricted Stock Units [Member]
Business Acquisition [Line Items]
Vesting period		4 years
Number of shares issued as part of acquisition | shares		295,600
Contingent consideration, contingency achievement period		4 years

Business Combinations - Purchas

Business Combinations - Purchase Price Allocation (Details) - USD ($) $ in Thousands	Oct. 15, 2018	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017	Dec. 31, 2016
Recognized amount of identifiable assets acquired and liabilities assumed:
Goodwill		$ 88,420	$ 83,164	$ 83,164	$ 75,110
tCell.io, Inc. [Member]
Business Acquisition [Line Items]
Cash consideration	$ 15,414
Recognized amount of identifiable assets acquired and liabilities assumed:
Cash and cash equivalents	1,089
Net working capital	(91)
Intangible asset	9,160
Total identifiable net assets assumed	10,158
Goodwill	5,256
Total purchase price allocation	$ 15,414

Business Combinations - Intangi

Business Combinations - Intangible Assets Acquired (Details) - tCell.io, Inc. [Member] - Developed Technology [Member] $ in Thousands	Oct. 15, 2018USD ($)
Business Acquisition [Line Items]
Developed technology	$ 9,160
Weighted Average Amortization Life (years)	5 years

Fair Value Measurements and I_3

Fair Value Measurements and Investments - Summary of Financial Assets and Liabilities Measured and Recorded at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	$ 204,102	$ 40,280
Convertible Debt [Member] | The Notes, Due 2023 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Stated interest percentage	1.25%
Convertible debt, fair value disclosures	$ 233,000
U.S. Government Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	71,483	11,869
Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	57,554	12,942
Corporate Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	48,495	12,964
US Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	19,087
Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	7,483	2,505
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets assets	262,746	40,375
Fair Value, Measurements, Recurring [Member] | U.S. Government Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	74,481	11,869
Fair Value, Measurements, Recurring [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	57,554	12,942
Fair Value, Measurements, Recurring [Member] | Corporate Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	48,495	12,964
Fair Value, Measurements, Recurring [Member] | US Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	19,087
Fair Value, Measurements, Recurring [Member] | Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	7,483	2,505
Fair Value, Measurements, Recurring [Member] | Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	55,646	95
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets assets	130,127	11,964
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. Government Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	74,481	11,869
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Corporate Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | US Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	55,646	95
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets assets	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. Government Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Corporate Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | US Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets assets	132,619	28,411
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. Government Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	57,554	12,942
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Corporate Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	48,495	12,964
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | US Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	19,087
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	7,483	2,505
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	$ 0	$ 0

Fair Value Measurements and I_4

Fair Value Measurements and Investments - Summary of Investments Classified as Available-for-sale (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 204,133	$ 40,319
Gross Unrealized Gains	51	0
Gross Unrealized Losses	(82)	(39)
Fair Value	$ 204,102	$ 40,280
Minimum [Member]
Debt Securities, Available-for-sale [Line Items]
Remaining maturity	3 months	3 months
Maximum [Member]
Debt Securities, Available-for-sale [Line Items]
Remaining maturity	2 years	2 years
U.S. Government Agencies [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 71,480	$ 11,880
Gross Unrealized Gains	20	0
Gross Unrealized Losses	(17)	(11)
Fair Value	71,483	11,869
U.S. Government Agencies [Member] | Available-for-sale Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Money market funds	3,000
Commercial Paper [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	57,554	12,942
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	57,554	12,942
Corporate Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	48,532	12,991
Gross Unrealized Gains	15	0
Gross Unrealized Losses	(52)	(27)
Fair Value	48,495	12,964
US Treasury Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	19,077
Gross Unrealized Gains	16
Gross Unrealized Losses	(6)
Fair Value	19,087
Asset-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	7,490	2,506
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(7)	(1)
Fair Value	$ 7,483	$ 2,505

Property and Equipment - Summar

Property and Equipment - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 43,741		$ 29,318
Less accumulated depreciation	(26,218)		(20,729)
Net property and equipment	17,523	$ 8,589	8,589
Construction in progress, gross	4,000
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	18,724		16,205
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	5,580		4,034
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 19,437		$ 9,079

Property and Equipment - Additi

Property and Equipment - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 6.5	$ 4.8	$ 4.3

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	$ 88,420,000	$ 83,164,000	$ 75,110,000	$ 83,164,000
Impairment of goodwill	0	0	0
Amortization expense	4,600,000	$ 2,800,000	$ 2,400,000
Capitalized internal-use software costs	$ 1,700,000

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Schedule of Change in Gross Carrying Amount of Goodwill (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 83,164	$ 75,110
Goodwill, ending balance	88,420	83,164
Komand, Inc. [Member]
Goodwill [Roll Forward]
Acquisition		$ 8,054
tCell.io, Inc. [Member]
Goodwill [Roll Forward]
Acquisition	$ 5,256

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Schedule of Identifiable Intangible Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Total acquired intangible assets, gross carrying amount	$ 31,330		$ 22,170
Total intangible assets, gross carrying amount	35,116		23,332
Accumulated Amortization	(11,161)		(6,692)
Total acquired intangible assets, accumulated amortization	(10,801)		(6,657)
Net Book Value	22,220
Total acquired intangible assets, net book value	20,529		15,513
Intangible assets, net book value	$ 23,955	$ 16,640	16,640
Developed Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted- Average Estimated Useful Life (years)	5 years 6 months
Gross Carrying Amount	$ 29,771		20,611
Accumulated Amortization	(9,741)		(5,756)
Net Book Value	$ 20,030		14,855
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted- Average Estimated Useful Life (years)	6 years 8 months 12 days
Gross Carrying Amount	$ 1,000		1,000
Accumulated Amortization	(504)		(351)
Net Book Value	$ 496		649
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted- Average Estimated Useful Life (years)	6 years 1 month 6 days
Gross Carrying Amount	$ 519		519
Accumulated Amortization	(516)		(510)
Net Book Value	$ 3		9
Non-compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted- Average Estimated Useful Life (years)	2 years
Gross Carrying Amount	$ 40		40
Accumulated Amortization	(40)		(40)
Net Book Value	0		0
Internal-use Software [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,786		1,162
Accumulated Amortization	(360)		(35)
Net Book Value	$ 3,426		$ 1,127

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets - Schedule of Estimated Amortization Expense (Detail) $ in Thousands	Dec. 31, 2018USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2,019	$ 6,251
2,020	6,193
2,021	5,398
2,022	2,927
2,023	1,451
2024 and thereafter	0
Net Book Value	$ 22,220

Convertible Senior Notes and _3

Convertible Senior Notes and Capped Calls - Additional Information (Details) $ / shares in Units, shares in Millions	1 Months Ended	12 Months Ended
	Aug. 31, 2018USD ($)day$ / sharesshares	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Debt Instrument [Line Items]
Proceeds from convertible debt		$ 223,121,000	$ 0	$ 0
Equity component of convertible debt, subsequent adjustments	$ 26,910,000
Financing arrangements		12,537,000	$ 0
Call Option [Member]
Debt Instrument [Line Items]
Strike price (in dollars per share) | $ / shares	$ 41.59
Cap price (in dollars per share) | $ / shares	$ 63.98
Option indexed to issuer's equity (in shares) | shares	5.5
Equity component of convertible debt, subsequent adjustments		26,900,000
Financing arrangements		13,000,000
Release of valuation allowance		$ 13,000,000
The Notes [Member]
Debt Instrument [Line Items]
Strike price (in dollars per share) | $ / shares	$ 41.59
Convertible Debt [Member] | The Notes, Due 2023 [Member]
Debt Instrument [Line Items]
Face amount	$ 200,000,000
Stated interest percentage		1.25%
Convertible Debt [Member] | The Notes, Over-allotment Option [Member]
Debt Instrument [Line Items]
Face amount	$ 30,000,000
Convertible Debt [Member] | The Notes [Member]
Debt Instrument [Line Items]
Stated interest percentage	1.25%
Proceeds from convertible debt	$ 223,100,000
Conversion ratio (in shares per $1000)	0.024046
Conversion price (in dollars per share) | $ / shares	$ 41.59
Redemption price, percentage	100.00%
Carrying amount of equity component	$ 53,800,000	$ 52,194,000
Convertible debt		174,688,000
Amortization of debt discount		3,486,000
Interest rate, effective percentage	7.36%
Debt issuance costs, net	$ 6,900,000	$ 4,978,000
Liability component	5,300,000
Convertible, issuance costs of equity component	$ 1,600,000
Debt Covenant One [Member] | Convertible Debt [Member] | The Notes [Member]
Debt Instrument [Line Items]
Threshold trading days | day	20
Threshold consecutive trading days | day	30
Threshold percentage of stock price trigger	130.00%
Debt Covenant Two [Member] | Convertible Debt [Member] | The Notes [Member]
Debt Instrument [Line Items]
Threshold trading days | day	5
Threshold percentage of stock price trigger	98.00%
Debt Covenant Three [Member] | Convertible Debt [Member] | The Notes [Member]
Debt Instrument [Line Items]
Threshold trading days | day	20
Threshold consecutive trading days | day	30
Threshold percentage of stock price trigger	130.00%
Redemption price, percentage	100.00%

Convertible Senior Notes and _4

Convertible Senior Notes and Capped Calls - Carrying Amount of Liability Component (Details) - Convertible Debt [Member] - The Notes [Member] - USD ($) $ in Thousands	Dec. 31, 2018	Aug. 31, 2018
Debt Instrument [Line Items]
Principal	$ 230,000
Unamortized debt discount	(50,334)
Unamortized issuance costs	(4,978)	$ (6,900)
Net carrying amount	$ 174,688

Convertible Senior Notes and _5

Convertible Senior Notes and Capped Calls - Carrying Amount of Equity Component (Details) - Convertible Debt [Member] - The Notes [Member] - USD ($) $ in Thousands	Dec. 31, 2018	Aug. 31, 2018
Debt Instrument [Line Items]
Debt discount for conversion option	$ 53,820
Issuance costs	(1,626)
Net carrying amount	$ 52,194	$ 53,800

Convertible Senior Notes and _6

Convertible Senior Notes and Capped Calls - Schedule of Interest Expense (Details) - Convertible Debt [Member] - The Notes [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)
Debt Instrument [Line Items]
Contractual interest expense	$ 1,103
Amortization of debt discount	3,486
Amortization of issuance costs	345
Total interest expense	$ 4,934

Convertible Senior Notes and _7

Convertible Senior Notes and Capped Calls - Future Payments of Contractual Interest (Details) - Convertible Debt [Member] - The Notes [Member] $ in Thousands	Dec. 31, 2018USD ($)
Principal
2,019	$ 0
2,020	0
2,021	0
2,022	0
2,023	230,000
Total	230,000
Interest
2,019	2,779
2,020	2,875
2,021	2,875
2,022	2,875
2,023	2,875
Total	14,279
Total
2,019	2,779
2,020	2,875
2,021	2,875
2,022	2,875
2,023	232,875
Total	$ 244,279

Convertible Senior Notes and _8

Convertible Senior Notes and Capped Calls - Impact to Shareholders' Equity (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Aug. 31, 2018	Dec. 31, 2018
Debt Instrument [Line Items]
Conversion option	$ 53,820
Purchase of capped calls	(26,910)
Issuance costs	(1,626)
Total	$ 25,284	$ 52,194

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	Jan. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Schedule Of Stockholders Equity [Line Items]
Number of stock issued (in shares)	5,950,000
Additional shares granted to underwriters (in shares)	770,000
IPO [Member]
Schedule Of Stockholders Equity [Line Items]
Offering price (in dollars per share)	$ 22
Net proceeds from issuance	$ 30.9
Existing Stockholders [Member]
Schedule Of Stockholders Equity [Line Items]
Number of stock issued (in shares)	4,450,000
Parent [Member]
Schedule Of Stockholders Equity [Line Items]
Number of stock issued (in shares)	1,500,000
Common Stock [Member]
Schedule Of Stockholders Equity [Line Items]
Number of stock issued (in shares)		1,500,000
Common stock repurchased during period (in shares)			22,754
Aggregate amount paid for share repurchase			$ 0.4

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Sep. 14, 2018	Mar. 15, 2018	Sep. 15, 2017	Mar. 15, 2017	Sep. 15, 2016	Mar. 15, 2016	Oct. 08, 2015	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016	Jul. 31, 2015	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Mar. 16, 2018	Sep. 18, 2017	Mar. 16, 2017	Mar. 16, 2016	Jul. 17, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period												4 years
Expiration period												10 years
Purchase price of common stock by employees												85.00%
Issuance of common stock under ESPP												$ 3,637	$ 2,914	$ 3,724
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted, weighted-average grant date fair value (in dollars per share)												$ 13.11	$ 9.38	$ 8.35
2015 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares of common stock reserved for future issuance (in shares)											800,000
Share-based compensation, increase in number of shares reserved and available for issuance as percentage under the plan											4.00%
Increase in number of shares authorized (in shares)							1,500,000	1,762,149	1,702,187	1,661,616
Number of shares authorized (in shares)												11,888,081
Shares available for grant (in shares)												998,777
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares of common stock reserved for future issuance (in shares)																			800,000
Increase in number of shares authorized (in shares)								440,537	425,547	415,404
Number of shares authorized (in shares)												2,081,488
Shares available for grant (in shares)												1,268,266
Issuance of common stock under ESPP (in shares)	96,108	123,607	109,144	138,085	153,602	192,676
Issuance of common stock under ESPP	$ 2,000	$ 1,600	$ 1,400	$ 1,500	$ 1,600	$ 2,100
Share issued, price per share (in dollars per share)				$ 12.79	$ 10.60	$ 10.88									$ 21.96	$ 14.78	$ 12.96	$ 10.60
Closing price of shares issued (in dollars per share)				$ 15.05		$ 12.80									$ 25.84	$ 17.39	$ 15.25	$ 12.47
Employee Stock Purchase Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted, weighted-average grant date fair value (in dollars per share)												$ 10.95	$ 5.35	$ 5.49
Employee withholding percentage												15.00%
Restricted Stock And Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost, restricted stock												$ 54,400
Unrecognized compensation, recognition period												2 years 8 months 12 days
Options to Purchase Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost, stock options												$ 6,400
Unrecognized compensation, recognition period												1 year 10 months 24 days
Stock options vested, fair value												$ 5,100	$ 5,900	$ 3,400
Stock options granted, weighted-average grant date fair value (in dollars per share)												$ 11.86	$ 6.72	$ 6.38

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 27,593	$ 19,541	$ 17,316
Cost of Revenue [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	1,692	1,085	610
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	10,822	7,205	6,054
Sales and Marketing [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	7,569	5,756	6,607
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 7,510	$ 5,495	$ 4,045

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Restricted Stock and Restricted Stock Unit Activity (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restricted Stock [Member]
Shares
Unvested balance, Beginning balance (in shares)	210,083	585,004	1,149,257
Granted (in shares)	0	0	0
Vested (in shares)	(187,706)	(358,214)	(538,896)
Forfeited (in shares)	(700)	(16,707)	(25,357)
Unvested balance, Ending balance (in shares)	21,677	210,083	585,004
Weighted- Average Grant Date Fair Value
Beginning balance (in dollars per share)	$ 18	$ 18.05	$ 19.34
Granted (in dollars per share)	0	0	0
Vested (in dollars per share)	18.80	17.85	20.67
Forfeited (in dollars per share)	23.01	23.01	20.96
Ending Balance (in dollars per share)	$ 10.88	$ 18	$ 18.05
Restricted Stock Units [Member]
Shares
Unvested balance, Beginning balance (in shares)	1,988,509	734,577	0
Granted (in shares)	2,099,394	1,938,860	919,397
Vested (in shares)	(973,443)	(435,573)	(91,020)
Forfeited (in shares)	(340,687)	(249,355)	(93,800)
Unvested balance, Ending balance (in shares)	2,773,773	1,988,509	734,577
Weighted- Average Grant Date Fair Value
Beginning balance (in dollars per share)	$ 14.77	$ 13.47	$ 0
Granted (in dollars per share)	25.19	14.97	13.37
Vested (in dollars per share)	17.41	13.80	12.93
Forfeited (in dollars per share)	18.96	14.22	12.97
Ending Balance (in dollars per share)	$ 21.21	$ 14.77	$ 13.47

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Shares
Beginning balance (in shares)	4,684,954	4,580,375	4,246,525
Granted (in shares)	107,850	1,304,238	1,454,626
Option assumed from acquisition (in shares)			0
Exercised (in shares)	(944,658)	(887,062)	(650,185)
Forfeited/cancelled (in shares)	(134,967)	(312,597)	(470,591)
Ending balance (in shares)	3,713,179	4,684,954	4,580,375
Vested and exercisable (in shares)	2,685,963
Weighted Average Exercise Price
Beginning balance (in dollars per share)	$ 9.68	$ 8.20	$ 5.99
Granted (in dollars per share)	24.44	13.52	13.43
Options assumed from acquisition (in dollars per share)			0
Exercised (in dollars per share)	8.05	6.59	4.43
Forfeited/cancelled (in dollars per share)	15.20	12.79	9.65
Ending balance (in dollars per share)	10.32	$ 9.68	$ 8.20
Vested and exercisable (in dollars per share)	$ 8.76
Weighted Average Remaining Contractual Life (in years)
Weighted Average Remaining Contractual Life, Outstanding	6 years 2 months 12 days
Weighted Average Remaining Contractual Life, Vested and exercisable	5 years 6 months 18 days
Aggregate Intrinsic Value (in thousands)
Stock options aggregate intrinsic value, Exercised	$ 19,982	$ 9,665	$ 6,409
Stock options aggregate intrinsic value, Outstanding	77,396
Stock options aggregate intrinsic value, Exercisable	$ 60,169

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Share Based Compensation Valuation of Options Granted Assumptions (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	6 years 1 month 6 days
Expected volatility, minimum	46.00%	48.00%	48.00%
Expected volatility, maximum	48.00%	52.00%	50.00%
Risk-free interest rate, minimum	2.40%	1.80%	1.20%
Risk-free interest rate, maximum	2.80%	2.20%	1.90%
Expected dividend yield	0.00%	0.00%	0.00%
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility, minimum		37.00%	42.00%
Expected volatility, maximum	37.00%	40.00%	49.00%
Risk-free interest rate, minimum	2.00%	0.90%	0.50%
Risk-free interest rate, maximum	2.60%	1.30%	0.70%
Expected dividend yield	0.00%	0.00%	0.00%
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term		5 years 6 months	5 years 6 months
Grant date fair value per share, maximum (in dollars per share)	$ 10.55	$ 6.09	$ 5.53
Minimum [Member] | Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	6 months	6 months	6 months
Grant date fair value per share, maximum (in dollars per share)	$ 6.62	$ 4.01	$ 3.58
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term		6 years 1 month 6 days	6 years 3 months 18 days
Grant date fair value per share, maximum (in dollars per share)	$ 13.11	$ 9.38	$ 8.35
Maximum [Member] | Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	1 year	1 year	1 year
Grant date fair value per share, maximum (in dollars per share)	$ 10.95	$ 5.35	$ 5.49

Income Taxes - Components of Lo

Income Taxes - Components of Loss Before Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
United States	$ (39,754)	$ (22,757)	$ (41,466)
Foreign	(15,325)	(24,949)	(7,561)
Loss before income taxes	$ (55,079)	$ (47,706)	$ (49,027)

Income Taxes - Summary of Incom

Income Taxes - Summary of Income Tax (Benefit) Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current:
Federal	$ 124	$ 333	$ 493
State and local	126	128	61
Foreign	228	163	(656)
Total current (benefit) expense	478	624	(102)
Deferred:
Federal	(285)	(2,885)	98
State and local	16	8	13
Foreign	257	17	(36)
Total deferred expense	(12)	(2,860)	75
Income tax expense (benefit)	$ 466	$ (2,236)	$ (27)

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating Loss Carryforwards [Line Items]
Provisional tax benefit recognized for Tax Act	$ 0.4
Tax benefit for remeasurement of deferred tax assets and liabilities	0.2
Provisional tax benefit for release of valuation allowance	0.2
Deferred tax provision			$ 0.1	$ 0.1
Net operating loss carryforwards, federal	171.2	$ 171.2	$ 50.3
Net operating loss carryforwards, state	118.7	118.7
Net operating loss carryforwards, foreign	93.1	93.1
Deferred Tax Assets Operating Loss Carryforwards [Member]
Operating Loss Carryforwards [Line Items]
Increase in valuation allowance		2.8
Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Research and development credit carryforwards	2.2	2.2
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Research and development credit carryforwards	1.1	1.1
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Research and development credit carryforwards	$ 0.1	$ 0.1

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Income Taxes Computed at Federal Statutory Rate and Provision for Income Taxes (Detail)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Expected income tax	21.00%	34.00%	34.00%
State taxes, net of federal benefit	(0.20%)	(0.20%)	(0.10%)
Permanent differences	0.20%	(0.40%)	(0.40%)
Stock compensation	9.30%	4.60%	(1.00%)
Federal research and development credit	1.20%	1.00%	2.40%
Foreign rate differential	(1.10%)	(8.70%)	(3.00%)
Change in valuation allowance	(32.80%)	(26.10%)	(31.90%)
Other	1.50%	0.50%	0.10%
Total income tax expense (benefit)	(0.90%)	4.70%	0.10%

Income Taxes - Components of Ne

Income Taxes - Components of Net Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Accruals and reserves	$ 397	$ 636
Net operating loss carryforwards	55,457	36,778
Deferred revenue	15,421	11,985
Depreciation	1,542	926
Research and development credits	3,440	2,441
Stock-based compensation	4,851	3,702
Tax credits	932	657
Other	953	557
Total deferred tax assets	82,993	57,682
Deferred tax liabilities:
Intangible assets	(1,104)	(616)
Convertible senior notes	(12,537)	0
Deferred contract acquisition and fulfillment costs	(9,796)	0
Other	(79)	0
Total deferred tax liabilities	(23,516)	(616)
Less: Valuation allowance	(60,130)	(57,359)
Net deferred tax liabilities	$ (653)	$ (293)

Income Taxes - Changes in Reser

Income Taxes - Changes in Reserves for Unrecognized Income Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ 29	$ 388
Decreases based on settlements with taxing authorities		(343)
Reductions based on lapse in statute of limitations	(17)	(16)
Ending balance	$ 12	$ 29

Net Loss Per Share - Summary of

Net Loss Per Share - Summary of Basic and Diluted Net Loss Per Share of Common Stock (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Numerator:
Net loss	$ (55,545)	$ (45,470)	$ (49,000)
Denominator:
Weighted-average common shares outstanding, basic and diluted (in shares)	46,456,825	42,952,950	41,248,473
Net loss per share, basic and diluted (in dollars per share)	$ (1.20)	$ (1.06)	$ (1.19)

Net Loss Per Share - Summary _2

Net Loss Per Share - Summary of Antidilutive Securities Excluded From Computation Diluted Weighted Average Shares Outstanding (Detail) - $ / shares	1 Months Ended	12 Months Ended
	Aug. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule Of Calculation Of Numerator And Denominator In Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount		6,583,263	6,963,097	5,991,771
The Notes [Member]
Schedule Of Calculation Of Numerator And Denominator In Earnings Per Share [Line Items]
Strike price (in dollars per share)	$ 41.59
Unvested Restricted Stock [Member]
Schedule Of Calculation Of Numerator And Denominator In Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount		21,677	210,083	585,004
Unvested Restricted Stock Units [Member]
Schedule Of Calculation Of Numerator And Denominator In Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount		2,773,773	1,988,509	734,577
Employee Stock Purchase Plan [Member]
Schedule Of Calculation Of Numerator And Denominator In Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount		74,634	79,551	91,815
Convertible Debt Securities [Member]
Schedule Of Calculation Of Numerator And Denominator In Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount		5,500,000
Options to Purchase Common Stock [Member]
Schedule Of Calculation Of Numerator And Denominator In Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount		3,713,179	4,684,954	4,580,375

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	Oct. 31, 2018patent	Dec. 31, 2018USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Commitments And Contingencies Disclosure [Line Items]
Rent expense			$ 7.5	$ 5.7	$ 5
Purchase obligation, due in next year		$ 42.5	42.5
Purchase obligation, due in second year		23.6	23.6
Purchase obligation, due in third year		25.8	25.8
Purchase obligation, due in fourth year		0.2	0.2
Purchase obligation, due in fifth year		0	0
Purchase obligation, due after fifth year		0.1	0.1
Settlement amount		0.6
Patents allegedly infringed, number | patent	7
Letter of Credit [Member]
Commitments And Contingencies Disclosure [Line Items]
Long-term line of credit		$ 8.2	$ 8.2

Commitments and Contingencies_2

Commitments and Contingencies - Future Minimum Operating Leases (Detail) $ in Thousands	Dec. 31, 2018USD ($)
Operating leases
2,019	$ 9,899
2,020	11,616
2,021	10,933
2,022	11,054
2,023	11,136
Thereafter	53,648
Total minimum lease payments	$ 108,286

Employee Benefit Plan - Additio

Employee Benefit Plan - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Retirement Benefits [Abstract]
Requisite service period for eligibility in 401(k) plan	90 days
Employer discretionary contributions	$ 2,000,000	$ 1,400,000	$ 0

Segment Information and Infor_3

Segment Information and Information about Geographic Areas - Additional Information (Detail) - Segment	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Number of operating segment	1
Sales Revenue, Net [Member] | United States [Member]
Segment Reporting Information [Line Items]
Concentration risk, percent	96.00%	93.00%	95.00%

Segment Information and Infor_4

Segment Information and Information about Geographic Areas - Net Revenues of Customer by Geographic Area (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues, Total	$ 244,091	$ 200,940	$ 157,437
North America [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues, Total	207,727	170,667	134,988
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues, Total	$ 36,364	$ 30,273	$ 22,449

Segment Information and Infor_5

Segment Information and Information about Geographic Areas - Property and Equipment, Net By Geographic Area (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	$ 17,523	$ 8,589	$ 8,589
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	16,311		7,182
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	$ 1,212		$ 1,407

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Intel Security [Member]
Related Party Transaction [Line Items]
Sales and marketing expense related to partner referral fees	$ 1.6	$ 1.9	$ 1.7

Uncategorized Items - rp-201812

Label	Element	Value
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 0
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	25,873,000
Additional Paid-in Capital [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	105,000
Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	(105,000)
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 25,873,000