Document and Entity Information - shares	9 Months Ended
Document and Entity Information - shares	Sep. 30, 2017	Oct. 31, 2017
Document and Entity Information [Line Items]
Entity Registrant Name	APPIAN CORP
Entity Central Index Key	0001441683
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q3
Amendment Flag	false
Trading Symbol	APPN
Class A Common Stock
Document and Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		7,206,517
Class B Common Stock
Document and Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		53,096,759

CONDENSED CONSOLIDATED BALANCE SHEETS (unaudited) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Current assets
Cash and cash equivalents	$ 72,289	$ 31,143
Accounts receivable, net of allowance of $400	41,399	46,814
Deferred commissions, current	7,719	7,146
Prepaid expenses and other current assets	6,318	3,281
Total current assets	127,725	88,384
Property and equipment, net	2,737	3,101
Deferred commissions, net of current portion	11,343	10,860
Deferred tax assets	107	12
Other assets	414	381
Total assets	142,326	102,738
Current liabilities
Accounts payable	2,712	5,057
Accrued expenses	5,977	2,860
Accrued compensation and related benefits	9,742	9,554
Deferred revenue, current	57,181	52,000
Current portion of long-term debt	0	6,111
Other current liabilities	574	437
Total current liabilities	76,186	76,019
Long-term debt, net of current portion	0	13,889
Deferred tax liabilities	35	32
Deferred revenue, net of current portion	14,577	18,108
Preferred stock warrant liability	0	850
Other long-term liabilities	1,624	1,917
Total liabilities	92,422	110,815
Stockholders’ equity (deficit)
Common stock	0	3
Additional paid-in capital	138,767	0
Accumulated other comprehensive income	451	1,330
Accumulated deficit	(89,320)	(64,825)
Total stockholders’ equity (deficit)	49,904	(63,492)
Total liabilities, convertible preferred stock and stockholders’ equity (deficit)	142,326	102,738
Series A Convertible Preferred Stock
Convertible preferred stock
Preferred stock	0	17,915
Series B Convertible Preferred Stock
Convertible preferred stock
Preferred stock	0	37,500
Class A Common Stock
Stockholders’ equity (deficit)
Common stock	1	0
Class B Common Stock
Stockholders’ equity (deficit)
Common stock	$ 5	$ 0

CONDENSED CONSOLIDATED BALANCE SHEETS (unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Allowance for doubtful accounts	$ 400	$ 400
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	0	61,462,320
Common stock, shares issued	0	34,274,718
Common stock, shares outstanding	0	34,274,718
Series A Convertible Preferred Stock
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	0	12,127,468
Preferred stock, shares issued	0	12,043,108
Preferred stock, shares outstanding	0	12,043,108
Series B Convertible Preferred Stock
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	0	6,120,050
Preferred stock, shares issued	0	6,120,050
Preferred stock, shares outstanding	0	6,120,050
Class A Common Stock
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	500,000,000	0
Common stock, shares issued	7,203,271	0
Common stock, shares outstanding	7,203,271	0
Class B Common Stock
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	100,000,000	0
Common stock, shares issued	53,073,459	0
Common stock, shares outstanding	53,073,459	0

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenue:
Subscriptions, software and support	$ 22,660	$ 17,668	$ 66,116	$ 50,607
Professional services	21,988	13,077	60,059	48,569
Total revenue	44,648	30,745	126,175	99,176
Cost of revenue:
Subscriptions, software and support	2,341	1,890	6,891	5,508
Professional services	14,272	9,315	39,049	34,016
Total cost of revenue	16,613	11,205	45,940	39,524
Gross profit	28,035	19,540	80,235	59,652
Operating expenses:
Sales and marketing	19,725	14,480	59,503	39,477
Research and development	8,596	6,702	25,867	16,925
General and administrative	6,237	4,531	19,721	12,779
Total operating expenses	34,558	25,713	105,091	69,181
Operating loss	(6,523)	(6,173)	(24,856)	(9,529)
Other (income) expense:
Other (income) expense, net	(425)	(67)	(1,658)	129
Interest (income) expense	(2)	243	451	726
Total other (income) expense	(427)	176	(1,207)	855
Net loss before income taxes	(6,096)	(6,349)	(23,649)	(10,384)
Income tax expense (benefit)	188	(1,610)	489	(2,106)
Net loss	(6,284)	(4,739)	(24,138)	(8,278)
Accretion of dividends on convertible preferred stock	0	214	357	642
Net loss attributable to common stockholders	$ (6,284)	$ (4,953)	$ (24,495)	$ (8,920)
Net loss per share attributable to common stockholders:
Basic and diluted (in dollar per share)	$ (0.10)	$ (0.14)	$ (0.53)	$ (0.26)
Weighted average common shares outstanding:
Basic and diluted (in shares)	60,204,596	34,274,718	45,855,044	34,274,718

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net loss	$ (6,284)	$ (4,739)	$ (24,138)	$ (8,278)
Comprehensive loss, net of income taxes:
Foreign currency translation adjustment	517	(177)	(879)	(537)
Total other comprehensive loss, net of income taxes	$ (5,767)	$ (4,916)	$ (25,017)	$ (8,815)

CONDENSED CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY (DEFICIT) (unaudited) - 9 months ended Sep. 30, 2017 - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Restricted Stock Units	Restricted Stock Units Common Stock
Balance, January 1, 2017 (in shares) at Dec. 31, 2016		34,274,718
Balance, January 1, 2017 at Dec. 31, 2016	$ (63,492)	$ 3		$ 1,330	$ (64,825)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(24,138)				(24,138)
Accretion of dividends on convertible preferred stock	(357)				(357)
Conversion of convertible preferred stock to common stock (in shares)		18,163,158
Conversion of convertible preferred stock to common stock	48,207	$ 2	$ 48,205
Conversion of convertible preferred stock warrant to common stock warrant	1,191		1,191
Issuance of common stock from initial public offering, net of issuance costs (in shares)		7,187,500
Issuance of common stock from initial public offering, net of issuance costs	$ 77,789	$ 1	77,788
Exercise of common stock warrant (in shares)		79,363
Issuance of common stock to directors (in shares)		10,841
Vesting of restricted stock units (in shares)						4,930	(4,930)
Exercise of stock options (in shares)	556,220	556,220
Exercise of stock options	$ 664		664
Stock-based compensation expense	10,919		10,919
Other comprehensive loss	(879)			(879)
Balance, September 30, 2017 (in shares) at Sep. 30, 2017		60,276,730
Balance, September 30, 2017 at Sep. 30, 2017	$ 49,904	$ 6	$ 138,767	$ 451	$ (89,320)

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities:
Net loss	$ (24,138)	$ (8,278)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	673	567
Bad debt expense	0	4
Deferred income taxes	(91)	(883)
Stock-based compensation	10,919	0
Fair value adjustment for warrant liability	341	200
Loss on extinguishment of debt	384	0
Changes in assets and liabilities:
Accounts receivable	4,329	6,208
Prepaid expenses and other assets	(3,184)	(2,360)
Deferred commissions	(1,056)	(1,389)
Accounts payable and accrued expenses	1,202	(2,931)
Accrued compensation and related benefits	(339)	1,617
Other current liabilities	(75)	(1,377)
Deferred revenue	1,043	374
Other long-term liabilities	(143)	433
Net cash used in operating activities	(10,135)	(7,815)
Cash flows from investing activities:
Purchases of property and equipment	(295)	(935)
Net cash used in investing activities	(295)	(935)
Cash flows from financing activities:
Proceeds from initial public offering, net of underwriting discounts	80,213	0
Payment of deferred initial public offering costs	(2,424)	0
Payment of dividend to Series A preferred stockholders	(7,565)	0
Proceeds from exercise of common stock options	664	0
Proceeds from issuance of long-term debt, net of debt issuance costs	19,616	20,000
Repayment of long-term debt	(40,000)	(10,000)
Net cash provided by financing activities	50,504	10,000
Effect of foreign exchange rate changes on cash and cash equivalents	1,072	(907)
Net increase in cash and cash equivalents	41,146	343
Cash and cash equivalents, beginning of period	31,143	31,393
Cash and cash equivalents, end of period	72,289	31,736
Supplemental disclosure of cash flow information:
Cash paid for interest	0	643
Cash paid for income taxes	484	580
Supplemental disclosure of non-cash financing activities:
Accretion of dividends on convertible preferred stock	357	642
Conversion of Convertible Preferred Stock to Common Stock
Supplemental disclosure of non-cash financing activities:
Conversion of convertible stock	48,207	0
Conversion of Convertible Preferred Stock Warrant to Common Stock Warrant
Supplemental disclosure of non-cash financing activities:
Conversion of convertible stock	$ 1,191	$ 0

Organization and Description of Business	9 Months Ended
Organization and Description of Business	Sep. 30, 2017
Accounting Policies [Abstract]
Organization and Description of Business	Organization and Description of Business Appian Corporation (together with its subsidiaries, “Appian,” the “Company,” “we” or “our”) provides a leading low-code software development platform that enables organizations to rapidly develop powerful and unique applications. The applications created on our platform help companies drive digital transformation and competitive differentiation. We were incorporated in the state of Delaware in August 1999. We are headquartered in Reston, Virginia and have offices in Canada, Switzerland, the United Kingdom, France, Germany, the Netherlands, Italy, and Australia.

Significant Accounting Policies

9 Months Ended

Sep. 30, 2017

Accounting Policies [Abstract]

Significant Accounting Policies

Basis of Presentation

The accompanying unaudited condensed consolidated financial statements and footnotes have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) as contained in the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (the “Codification” or “ASC”) for interim financial information. In the opinion of management, the interim financial information includes all adjustments of a normal recurring nature necessary for a fair presentation of the results of operations, financial position, changes in stockholders’ equity (deficit) and cash flows. The results of operations for the current period are not necessarily indicative of the results for the full year or the results for any future periods. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related footnotes included in our final prospectus for our initial public offering (“IPO”) dated as of May 24, 2017 and filed with the Securities and Exchange Commission (the “SEC”) pursuant to Rule 424(b)(4) under the Securities Act of 1933, as amended.

Use of Estimates

The preparation of our condensed consolidated financial statements in conformity with U.S. GAAP requires us to make estimates and judgments that affect the amounts reported in these condensed consolidated financial statements and accompanying notes. Although we believe that the estimates we use are reasonable, due to the inherent uncertainty involved in making these estimates, actual results reported in future periods could differ from those estimates.

Significant estimates embedded in the condensed consolidated financial statements include revenue recognition, income taxes and the related valuation allowance, stock-based compensation and fair value measurements for our common stock and preferred stock warrant.

Principles of Consolidation

The accompanying condensed consolidated financial statements include the accounts of Appian and its wholly-owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.

Initial Public Offering

In May 2017, we completed an IPO in which we sold 7,187,500 shares of our newly-authorized Class A common stock at an initial price to the public of $12.00 per share. We received net proceeds of $77.8 million, after deducting underwriting discounts and commissions and offering expenses paid and payable by us, from sales of our shares in the IPO. Immediately prior to the completion of the IPO, (1) all shares of common stock then outstanding were converted into Class B common stock on a one-for-one basis, (2) a warrant to purchase shares of convertible preferred stock was converted into a warrant to purchase shares of Class B common stock and (3) all shares of convertible preferred stock then outstanding were converted into shares of our common stock on a one-for-one basis, and then reclassified as shares of Class B common stock. See Note 7 for further discussion of the convertible preferred stock and Note 8 for further discussion of the warrant.

Deferred offering costs of $2.4 million, consisting of legal, accounting and other fees and costs related to our IPO, were recorded to additional paid-in capital as a reduction of the proceeds upon the closing of our IPO.

Revenue Recognition

We generate revenue primarily through sales of subscriptions to our platform, as well as professional services. We recognize revenue when all of the following conditions are met: (1) there is persuasive evidence of an arrangement; (2) the service or product has been provided to the customer; (3) the amount of fees to be paid by the customer is fixed or determinable; and (4) the collection of related fees is reasonably assured. If collection is not reasonably assured, we defer revenue recognition until collectability becomes reasonably assured. Our arrangements do not contain general rights of return. Revenue is recognized net of any taxes collected from customers and subsequently remitted to governmental authorities.

Subscriptions, Software and Support Revenue

Subscriptions, software and support revenue is primarily related to (1) software as a service (“SaaS”) subscriptions bundled with maintenance and support and hosting services and (2) term license subscriptions bundled with maintenance and support. To a lesser extent, we also generate revenue from the sale of perpetual software licenses and associated maintenance and support.

Historically, we licensed our software primarily under perpetual licenses, but over time we transitioned from perpetual licenses to subscriptions. As a result, revenue from our perpetual software licenses was less than 1.0% of our total revenue for the three and nine months ended September 30, 2017 and September 30, 2016.

We generally charge subscription fees on a per-user basis. We bill customers and collect payment for subscriptions to our platform in advance on a monthly, quarterly or annual basis. In certain instances, we have had customers pay their entire contract up front.

SaaS Subscriptions

Our SaaS subscription revenue is derived from customers accessing our cloud offering pursuant to contracts that are generally one to five years in length. We perform all required maintenance and support for our cloud offering and we do not separately charge customers for hosting costs. In these arrangements, our customers do not have the right to take the software on-premises and, as a result, such arrangements are not accounted for within the scope of the software revenue guidance. Revenue from SaaS subscriptions is recognized ratably over the term of the subscription, beginning with the date our service is made available to our customer.

Term License Subscriptions

Our term license subscription revenue is derived from customers with on-premises installations of our platform pursuant to contracts that are generally one to five years in length. Customers with term license subscriptions have the right to use our software and receive maintenance and support. Since we do not sell maintenance and support separately from the subscription, revenue for the term license subscription and maintenance and support is recognized ratably over the term of the subscription, upon delivery of the platform to the customer when sold on a standalone basis.

Perpetual Licenses

Our perpetual license revenue is derived from customers with perpetual licenses to our platform and associated maintenance and support contracts. We recognize revenue from perpetual licenses on the date of delivery to our customer. We sell maintenance and support to perpetual license customers separately from the perpetual licenses pursuant to agreements that generally renew annually. Maintenance and support revenue is deferred and recognized ratably over the term of the support period.

Professional Services

Our professional services revenue is comprised of fees for consulting services, including application development and deployment assistance and training related to our platform. Our professional services are not essential to the functionality of our platform because the platform is ready for the customer’s use immediately upon delivery and is not modified or customized in any manner.

Consulting services are billed under both time-and-material and fixed-fee arrangements. For standalone time-and-material contracts, we recognize revenue at contractually agreed upon billing rates applied to hours performed, plus the cost of any materials delivered. For standalone fixed-fee contracts, we also recognize revenue as the work is performed using the proportional performance method of accounting. Training revenue is recognized when the associated training services are delivered. Training is also sold in the form of a subscription arrangement where a customer agrees to pay an annual fixed fee for a fixed number of users to have access to all of our training offerings during the year. Revenue from training subscription agreements is recognized ratably over the subscription period.

We defer recognition of revenue from work performed on pending contract modifications until the period in which the modifications are accepted and funding is approved by the customer. Costs of work performed on pending contract modifications are expensed as incurred.

Multiple Element Arrangements

Our multiple element arrangements are from SaaS subscriptions, term license subscriptions, and perpetual licenses that are generally sold in combination with maintenance and support service and frequently with professional services.

SaaS Subscriptions

For multiple element arrangements involving SaaS subscriptions that include professional services in addition to the subscription to our platform, we evaluate each element to determine whether it represents a separate unit of accounting. Because there are third-party vendors who routinely sell and provide the same professional services to our customers, our professional services are deemed to have standalone value apart from the SaaS subscription. Additionally, we offer both SaaS subscriptions and professional services on a standalone basis. Professional services revenue is therefore accounted for separately from subscription fees and recognized as the professional services are performed. We allocate revenue to the elements based on the selling price hierarchy using vendor-specific objective evidence (“VSOE”) of selling price, third-party evidence (“TPE”) of selling price, or if neither exists, best estimated selling price (“BESP”). In cases where we do not have VSOE or TPE of the elements of our arrangements, we use BESP to allocate revenue. We determine BESP for a service by considering multiple factors including, but not limited to, evaluating the weighted average of actual sales prices and other factors such as gross margin objectives, pricing practices and growth strategy. Pricing practices taken into consideration include historic contractually stated prices, volume discounts where applicable and our price lists. While we believe we can make reliable estimates regarding these matters, these estimates are inherently subjective. Once the revenue is allocated to these elements, revenue is recognized as such services are provided.

Term License Subscriptions

For multiple element arrangements involving term license subscriptions, maintenance and support and professional services, we do not have VSOE of fair value for the maintenance and support. Our term license subscriptions are generally not sold on a standalone basis, and therefore, we have not established VSOE of fair value for the subscriptions. Consequently, for our bundled arrangements that include certain professional services, there are two undelivered elements for which VSOE of fair value has not been established and, therefore, we utilize the combined services approach and defer all revenue until the software has been delivered and the provision of all services has commenced. We then recognize the entire fee from the arrangement ratably over the remaining period of the arrangement, assuming all other software revenue recognition criteria have been met.

Perpetual Licenses

For multiple element arrangements involving our perpetual software licenses, we allocate revenue to the software license arrangement by determining if VSOE of fair value exists for the undelivered elements, which are usually maintenance and support and professional services. In situations where VSOE of fair value exists for the undelivered elements, we apply the residual method whereby the fees allocated to license revenue are recognized upon delivery, the fees allocated to maintenance and support revenue are recognized over the service period and the fees allocated to professional services and training are recognized as performed. In instances where we lack VSOE of fair value for the undelivered elements, revenue is either deferred until the final element is delivered or recognized ratably over the service period when the only undelivered elements are either professional services or maintenance and support. We have VSOE for maintenance and support elements and professional services elements performed on a time and materials basis. VSOE of fair value is based upon the price charged when the same element is sold separately. In determining VSOE of fair value, we require that a substantial majority of the selling prices fall within a reasonably narrow pricing range. We reassess VSOE annually or more frequently if required.

Deferred Revenue

Deferred revenue primarily consists of amounts billed or billable in advance of revenue recognition from our subscriptions, software, and support and professional services described above. Deferred revenue is recognized as the revenue recognition criteria are met.

Cost of Revenue

Cost of Subscriptions, Software and Support Revenue

Cost of subscriptions, software and support revenue consists primarily of fees paid to our third-party managed hosting providers and other third-party service providers, personnel costs, including payroll and benefits for our technology operations and customer support teams, and allocated facility costs and overhead.

Cost of Professional Services Revenue

Cost of professional services revenue includes all direct and indirect costs to deliver our professional services and training, including employee compensation for our global professional services and training personnel, travel costs, third-party contractor costs and allocated facility costs and overhead.

Concentration of Credit Risk

Our financial instruments that are exposed to concentration of credit risk consist primarily of cash and cash equivalents and trade accounts receivable. Cash deposits may be in excess of insured limits. We believe that the financial institutions that hold our cash deposits are financially sound and, accordingly, minimal credit risk exists with respect to these balances.

With regard to our customers, credit evaluation and account monitoring procedures are used to minimize the risk of loss. We believe that no additional credit risk beyond amounts provided for collection loss are inherent in accounts receivable. Revenue generated from government agencies represented 14.2% and 15.4% of our revenue for the three and nine months ended September 30, 2017, respectively, of which the top three federal government agencies generated 7.7% and 9.1% of our revenue for the three and nine months ended September 30, 2017, respectively. Additionally, 28.6% and 25.6% of our revenue during the three and nine months ended September 30, 2017, respectively, was generated from foreign customers. Revenue generated from government agencies represented 19.4% and 28.5% of our revenue for the three and nine months ended September 30, 2016, respectively, of which the top three federal government agencies generated 13.1% and 19.5% of our revenue for the three and nine months ended September 30, 2016, respectively. Additionally, 23.1% and 18.6% of our revenue during the three and nine months ended September 30, 2016, respectively, was generated from foreign customers.

Federal government agencies accounted for 9.1% and 17.2% of accounts receivable at September 30, 2017 and December 31, 2016, respectively.

Accounts Receivable and Allowance for Doubtful Accounts

Accounts receivable are stated at realizable value, net of an allowance for doubtful accounts. The allowance for doubtful accounts is based on our assessment of the collectability of accounts. We regularly review the composition of the accounts receivable aging, historical bad debts, changes in payment patterns, customer creditworthiness and current economic trends. If the financial condition of our customers were to deteriorate, resulting in their inability to make required payments, additional provisions for doubtful accounts would be required and would increase bad debt expense. To date, our allowance and related bad debt write-offs have been nominal. There was no change in the allowance for doubtful accounts from December 31, 2016 to September 30, 2017.

Deferred Commissions

Deferred commissions are the incremental costs that are directly associated with subscription agreements with customers and consist of sales commissions paid to our direct sales force. Commissions are considered direct and incremental and as such are deferred and amortized over the terms of the related customer contracts consistent with the related revenue. Amortization of deferred commissions is included in sales and marketing expense in the accompanying condensed consolidated statements of operations. Commission expense was $3.2 million and $8.5 million for the three and nine months ended September 30, 2017, respectively. Commission expense was $1.8 million and $5.4 million for the three and nine months ended September 30, 2016, respectively.

Fair Value of Financial Instruments

The carrying amounts of our cash and cash equivalents, accounts receivable, accounts payable and accrued expenses approximate fair value as of September 30, 2017 and December 31, 2016 because of the relatively short duration of these instruments. The carrying value of our long-term debt as of December 31, 2016 approximated fair value given interest rates for similar debt instruments available to the Company.

We use a three-tier fair value hierarchy to classify and disclose all assets and liabilities measured at fair value on a recurring basis, as well as assets and liabilities measured at fair value on a non-recurring basis, in periods subsequent to their initial measurement. The hierarchy requires us to use observable inputs when available, and to minimize the use of unobservable inputs when determining fair value. The three tiers are defined as follows:


•	Level 1. Observable inputs based on unadjusted quoted prices in active markets for identical assets or liabilities;


•	Level 2. Inputs, other than quoted prices in active markets, that are observable either directly or indirectly; and


•	Level 3. Unobservable inputs for which there is little or no market data, which require us to develop our own assumptions.

Assets and Liabilities Measured at Fair Value on a Recurring Basis

We evaluate our financial assets and liabilities subject to fair value measurements on a recurring basis to determine the appropriate level in which to classify them for each reporting period. This determination requires significant judgments to be made. After the reclassification of the convertible preferred stock warrant in May 2017, we did not have any assets or liabilities subject to fair value measurements as of September 30, 2017. See Note 8 for further discussion of the warrant reclassification. The following table summarizes the conclusions reached as of December 31, 2016 (in thousands):



	December 31, 2016		Level 1		Level 2		Level 3
Liabilities:
Series A convertible preferred stock warrant(1)	$	850	$	—	$	—	$	850
	$	850	$	—	$	—	$	850

_______________________________________________

(1)

In order to determine the fair value of the convertible preferred stock warrant, we used the Black-Scholes option pricing model (“OPM”). Significant inputs for the OPM included an estimate of the fair value of the Series A convertible preferred stock, the remaining contractual life of the warrant, an estimate of the timing of a liquidity event, a risk-free rate of interest and an estimate of our stock volatility using the volatilities of guideline peer companies.

Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs

There were no changes in our Level 3 instruments measured at fair value on a recurring basis during the three months ended September 30, 2017 and 2016.

The following table presents the changes in our Level 3 instruments measured at fair value on a recurring basis during the nine months ended September 30, 2017 and 2016 (in thousands):



	Nine Months Ended September 30,
	2017			2016
Balance as of January 1	$	850		$	650
Change in fair value of warrant liability	341			200
Reclassification of warrant liability to equity	(1,191		)	—
Balance as of September 30	$	—		$	850

Stock-Based Compensation

We account for stock-based compensation expense related to stock-based awards based on the estimated fair value of the award on the grant date. We calculate the fair value of stock options using the Black-Scholes OPM. For service-based awards, stock-based compensation expense is recognized on a straight-line basis over the requisite service period. For performance-based awards, stock-based compensation expense is recognized using the accelerated attribution method, based on the probability of satisfying the performance condition. For awards that contain market conditions, compensation expense is measured using a Monte Carlo simulation model and recognized using the accelerated attribution method over the derived service period based on the expected market performance as of the grant date. For restricted stock units, stock-based compensation expense is recognized on a straight-line basis over the requisite service period.

As discussed in “—Recent Accounting Pronouncements,” we have elected to early adopt Accounting Standards Update (“ASU”) No. 2016-9, which, among other things, permits an entity to make an entity-wide policy election to either (1) estimate the number of awards that are expected to vest or (2) account for forfeitures when they occur. We have elected to account for forfeitures as they occur, rather than estimate expected forfeitures.

Emerging Growth Company Status

We are an “emerging growth company” as defined in the Jumpstart Our Business Startups Act (“JOBS Act”). The JOBS Act provides that an emerging growth company can take advantage of an extended transition period for complying with new or revised accounting standards. Thus, an emerging growth company can delay the adoption of certain accounting standards until those standards would otherwise apply to private companies. We have elected to avail ourselves of this extended transition period and, as a result, we will not adopt new or revised accounting standards on the relevant dates on which adoption of such standards is required for other public companies.

Recent Accounting Pronouncements

Adopted

In August 2014, the FASB issued ASU No. 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (“ASU 2014-15”), which amends ASC Subtopic 205-40 to provide guidance about management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related disclosures. Specifically, the amendments (1) provide a definition of the term “substantial doubt,” (2) require an evaluation of every reporting period, (3) provide principles for considering the mitigating effect of management’s plans, (4) require certain disclosures when substantial doubt is alleviated as a result of consideration of management’s plans, (5) require an express statement and other disclosures when substantial doubt is not alleviated and (6) require an assessment for a period of one year after the date that financial statements are issued. ASU 2014-15 was effective for our year ended December 31, 2016, and its adoption did not have a material impact on our financial condition, results of operations or cash flows.

In April 2015, the FASB issued ASU No. 2015-3, Simplifying the Presentation of Debt Issuance Costs (“ASU 2015-3”), which simplifies the presentation of debt issuance costs by requiring that such costs be presented in the condensed consolidated balance sheets as a direct deduction from the carrying value of the associated debt instrument, consistent with debt discounts. Subsequent to the issuance of ASU 2015-3, the SEC staff announced that the presentation of debt issuance costs associated with line-of-credit arrangements may be presented as an asset. This announcement was codified by the FASB in ASU No. 2015-15, Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements (“ASU 2015-15”). ASU 2015-3 and ASU 2015-15 were both effective for our year ended December 31, 2016, and their adoption did not have a material impact on our financial condition, results of operations or cash flows.

In April 2015, the FASB issued ASU No. 2015-5, Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement (“ASU 2015-5”), which provides clarification on whether a cloud computing arrangement includes a software license. If a software license is included, the customer should account for the license consistent with its accounting for other software licenses. If a software license is not included, the arrangement should be accounted for as a service contract. ASU 2015-5 was effective for our year ended December 31, 2016, and its adoption did not have a material impact on our financial condition, results of operations or cash flows.

In November 2015, the FASB issued ASU No. 2015-17, Balance Sheet Classification of Deferred Taxes (Topic 740) (“ASU 2015-17”), which requires that all deferred tax assets and liabilities, including any related valuation allowance, be classified as noncurrent on the balance sheet. We elected to early adopt ASU 2015-17 beginning with our year ended December 31, 2015. The adoption of ASU 2015-17 did not have a material impact on our financial condition, results of operations or cash flows.

In March 2016, the FASB issued ASU No. 2016-9, Improvements to Employee Share-Based Payment Accounting (Topic 718) (“ASU 2016-9”), which is intended to simplify several aspects of the accounting for share-based payment transactions, including the accounting for income taxes, forfeitures, and statutory tax withholding requirements, as well as classification in the statement of cash flows. We elected to early adopt ASU 2016-9 beginning with our year ended December 31, 2016, and have applied the guidance retrospectively. The adoption of ASU 2016-9 did not have a material impact on our financial condition, results of operations or cash flows.

Not Yet Adopted

In May 2014, the FASB issued ASU No. 2014-9, Revenue from Contracts with Customers (Topic 606)(“ASU 2014-9”), which provides new guidance for revenue recognition. ASU 2014-9 provides that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ASU 2014-9 also requires improved disclosures to help users of financial statements better understand the nature, amount, timing, and uncertainty of revenue that is recognized. Entities have the option of using either a full retrospective or modified retrospective approach for the adoption of the standard. In March 2016, the FASB issued ASU No. 2016-8, Principal Versus Agent Considerations (Reporting Revenue Gross Versus Net) (“ASU 2016-8”), which clarifies implementation guidance on principal versus agent considerations in ASU 2014-9. In April 2016, the FASB issued ASU No. 2016-10, Identifying Performance Obligations and Licensing (“ASU 2016-10”), which clarifies the identification of performance obligations and the licensing implementation guidance in ASU 2014-9. In addition, in May 2016, the FASB issued ASU No. 2016-12, Narrow-Scope Improvements and Practical Expedients (“ASU 2016-12”), which clarifies the guidance on assessing collectibility, presentation of sales taxes, noncash consideration and completed contracts and contract modifications at transition. For public entities, the new standard is effective for annual periods and interim periods within those annual periods, beginning after December 15, 2017. For all other entities, the new standard is effective for annual periods beginning after December 15, 2018, and interim periods within those annual periods beginning after December 15, 2019. We intend to avail ourselves of the JOBS Act extended transition period that permits us to defer adoption until January 1, 2019. We are currently evaluating the impact the adoption of these standards will have on our consolidated financial statements.

We currently plan to adopt the new standard using the full retrospective approach; however, the decision regarding the adoption method has not been finalized. Our final determination will depend on a number of factors such as the significance of the impact of the new standard on our financial results, system readiness, including that of software procured from third-party providers, and our ability to accumulate and analyze the information necessary to assess the impact on prior period financial statements, as necessary.

We are in the initial stages of our evaluation of the impact of the new standard on our accounting policies, processes, and system requirements. We have assigned internal resources in addition to the engagement of third-party service providers to assist in the evaluation. Furthermore, we have made and will continue to make investments in systems to enable timely and accurate reporting under the new standard. While we continue to assess all potential impacts under the new standard there is the potential for significant impacts to the timing of recognition of revenue, particularly term license subscriptions and professional services revenue. We also expect an impact to our accounting for contract acquisition costs, both with respect to the amounts that will be capitalized as well as the period of amortization.

Under current industry-specific software revenue recognition guidance, we have historically concluded that we did not have VSOE of fair value of the undelivered services related to term license subscriptions, and accordingly, have recognized term license subscriptions and related services ratably over the subscription term. Professional services included in an arrangement with subscription revenue has also been recognized ratably over the subscription term. The new standard, which does not retain the concept of VSOE, requires an evaluation of whether term license subscriptions and related services, including professional services, are distinct performance obligations and therefore should be separately recognized at a point in time or over time. Depending on the outcome of our evaluation, the timing of when revenue is recognized could change significantly for term license subscriptions and professional services under the new standard.

In February 2016, the FASB issued ASU No. 2016-2, Leases (Topic 842) (“ASU 2016-2”), which requires that lessees recognize assets and liabilities for leases with lease terms greater than 12 months in the statement of financial position. ASU 2016-2 also requires improved disclosures to help users of financial statements better understand the amount, timing and uncertainty of cash flows arising from leases. The update is effective for fiscal years beginning after December 15, 2019, and interim periods within fiscal years beginning after December 15, 2020. Early adoption is permitted. We are currently evaluating the impact the adoption of ASU 2016-2 will have on our consolidated financial statements.

In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (“ASU 2016-15”), which aims to reduce the existing diversity in practice in how certain cash receipts and cash payments are presented and classified in the statement of cash flows. ASU 2016-15 will require adoption on a retrospective basis unless it is impracticable to apply, in which case we would be required to apply the amendments prospectively as of the earliest date practicable. ASU 2016-15 is effective for fiscal years beginning after December 15, 2018, and interim periods within fiscal years beginning after December 15, 2019. Early adoption is permitted. We are currently in the process of evaluating the impact of adoption of this standard on our consolidated financial statements.

Debt	9 Months Ended
Debt	Sep. 30, 2017
Debt Disclosure [Abstract]
Debt	Debt 2015 Line of Credit At December 31, 2015, we had a $10.0 million revolving line of credit with a lender, expiring in June 2016, which was subsequently amended in June 2016 to extend the maturity date through June 2017. This line of credit was terminated in April 2017. 2015 Term Loan In March 2015, we entered into a collateralized $10.0 million term loan facility with a lender, maturing in March 2019, and borrowed the full amount under the term loan facility in June 2015. In January 2016, we paid off the outstanding balance of the term loan and simultaneously entered into a collateralized $20.0 million term loan facility, maturing in January 2020. We borrowed the full amount under the term loan facility in January 2016, which we repaid in full in April 2017. 2017 Financing Facility In April 2017, we entered into a new financing facility consisting of a $5.0 million senior revolving credit facility, a $20.0 million senior term loan, and a $10.0 million subordinated term loan. In connection with the execution of this financing facility, the prior line of credit was terminated, and we borrowed the full $20.0 million available under the senior term loan and repaid the outstanding balance under our prior term loan. Additionally, in connection with the execution of our new financing facility, the lender waived the prepayment fee associated with our prior line of credit. In June 2017, we used proceeds from our IPO to pay all remaining outstanding principal and interest under the senior term loan and subsequently terminated the senior term loan and subordinated term loan. In connection with the repayment of the senior term loan, we recognized a loss on extinguishment of debt of $0.4 million related to unamortized debt issuance costs, which is included within other (income) expense, net in the accompanying condensed consolidated statements of operations. As of September 30, 2017, we had no outstanding borrowings. This financing facility was terminated in November 2017 in connection with our entry into a new $20.0 million revolving line of credit. See Note 11 for additional information regarding our new revolving line of credit.

Income Taxes	9 Months Ended
Income Taxes	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The provision for income taxes is based upon the estimated annual effective tax rates for the year applied to the current period income (loss) before tax plus the tax effect of any significant unusual items, discrete events or changes in tax law. Our operating subsidiaries are exposed to statutory effective tax rates ranging from zero to approximately 40%. Fluctuations in the distribution of pre-tax income (loss) among our operating subsidiaries can lead to fluctuations of the effective tax rate in the consolidated financial statements. For the three and nine months ended September 30, 2017, the actual effective tax rates were (3.1)% and (2.1)%, respectively. For the three and nine months ended September 30, 2016, the actual effective tax rates were 25.4% and 20.3%, respectively. We assess uncertain tax positions in accordance with ASC 740-10, Accounting for Uncertainties in Tax. As of September 30, 2017, our net unrecognized tax benefits totaled $0.5 million of which the entire portion would impact our effective tax rate if recognized. We anticipate that the amount of reasonably possible unrecognized tax benefits that could decrease over the next 12 months due to the expiration of certain statutes of limitations and settlement of tax audits is not material to our consolidated financial statements. We file income tax returns in the United States federal jurisdiction and in many state and foreign jurisdictions. The tax years 2013 through 2016 remain open to examination by the major taxing jurisdictions to which we are subject. No material examinations are currently open.

Stock-Based Compensation

9 Months Ended

Sep. 30, 2017

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Stock-Based Compensation

In May 2017, our board of directors adopted, and our stockholders approved, the 2017 Equity Incentive Plan (the “2017 Plan”), which became effective as of the date of the final prospectus for our IPO. The 2017 Plan provides for the grant of incentive stock options to employees, and for the grant of nonstatutory stock options, restricted stock awards, restricted stock unit awards, stock appreciation rights, performance-based stock awards and other forms of equity compensation to employees, including officers, and to non-employee directors and consultants. We initially reserved 6,421,442 shares of Class A common stock for issuance under the 2017 Plan, which included 421,442 shares that remained available for issuance under our 2007 Stock Option Plan (the “2007 Plan”) at the time that the 2017 Plan became effective. The number of shares reserved under the 2017 Plan increases for any shares subject to outstanding awards originally granted under the 2007 Plan that expire or are forfeited prior to exercise. As a result of the adoption of the 2017 Plan, no further grants may be made under the 2007 Plan. As of September 30, 2017, there were 6,481,622 shares of Class A common stock reserved for issuance under the 2017 Plan, of which 6,425,767 were available to be issued.

The 2007 Plan provided for the grant of stock options to employees, directors, and officers. Options under the 2007 Plan are exercisable into shares of Class B common stock and generally expire ten years from the date of grant. Under the 2007 Plan, the exercise price of each award was established by the board of directors, but could not be less than the fair market value of a share of our common stock on the grant date. Options generally vest upon the satisfaction of both a service condition and a performance condition. The service condition is satisfied at various rates as determined by us, typically on an annual basis over five years. The performance condition required the occurrence of a qualifying event, defined as a change of control transaction or upon the completion of an IPO. The performance condition was satisfied upon the effectiveness of our IPO in May 2017, on which date we recognized $6.2 million of cumulative stock-based compensation expense using the accelerated attribution method from the service start date.

We estimate the fair value of stock options using the Black-Scholes OPM, which requires the use of subjective assumptions, including the expected term of the option, the current price of the underlying stock, the expected stock price volatility, expected dividend yield and the risk-free interest rate for the expected term of the option. The expected term represents the period of time the stock options are expected to be outstanding. Due to the lack of sufficient historical exercise data to provide a reasonable basis upon which to otherwise estimate the expected term of the stock options, we use the simplified method to estimate the expected term for our stock options. Under the simplified method, the expected term of an option is presumed to be the mid-point between the vesting date and the end of the contractual term. Expected volatility is based on historical volatilities for publicly traded stock of comparable companies over the estimated expected term of the stock options. We assume no dividend yield because dividends are not expected to be paid in the near future, which is consistent with our history of not paying dividends.

The following table summarizes the assumptions used to estimate the fair value of stock options granted during the three and nine months ended September 30, 2017 and 2016:



	Three Months Ended September 30,		Nine Months Ended September 30,
	2017	2016	2017	2016
Risk-free interest rate	1.9% - 2.1%	1.3%	1.9% - 2.2%	1.3% - 1.5%
Expected term (in years)	6.5	6.5	6.5	6.5
Expected volatility	38.6%	41.6%	38.6% - 40.6%	41.2% - 42.0%
Expected dividend yield	—%	—%	—%	—%

Stock Options

The following table summarizes the stock option activity for the nine months ended September 30, 2017:



	Number of Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value (in thousands)
Outstanding at January 1, 2017	6,784,448		$	4.65	6.5	$	44,259
Granted	1,252,200		11.89
Exercised	(556,220	)	1.19			8,386
Canceled	(96,500	)	6.30
Outstanding at September 30, 2017	7,383,928		6.16		6.7	164,688
Exercisable at September 30, 2017	2,992,648		1.85		3.8	79,636

The weighted average grant-date fair value of options granted during the nine months ended September 30, 2017 and 2016 was $5.04 and $4.38 per share, respectively. The total fair value of stock options that vested during the nine months ended September 30, 2017 was $5.3 million. No stock options vested during the nine months ended September 30, 2016 because a qualifying event had not yet occurred. As of September 30, 2017, the total compensation cost related to unvested stock options not yet recognized was $12.6 million, which will be recognized over a weighted average period of 3.0 years.

On April 25, 2017, our board of directors modified certain outstanding stock options nearing their expiration date to remove the performance condition. Stock options to purchase an aggregate of 216,160 shares of common stock were modified, and we recognized stock-based compensation expense of $2.4 million related to this modification.

Restricted Stock Units

The following table summarizes the restricted stock unit activity for the nine months ended September 30, 2017:



	Number of Shares		Weighted Average Grant Date Fair Value
Non-vested outstanding at December 31, 2016	—		$	—
Granted	47,855		20.38
Vested	(4,930	)	20.24
Canceled	—		—
Non-vested outstanding at September 30, 2017	42,925		20.40

As of September 30, 2017, total unrecognized compensation cost related to unvested restricted stock units was approximately $0.8 million and the weighted average remaining vesting period was 2.7 years.

The following table summarizes the components of our stock-based compensation expense for the three and nine months ended September 30, 2017 (in thousands):



	Three Months Ended		Nine Months Ended
	September 30, 2017		September 30, 2017
Stock-based compensation expense related to stock option modifications	$	—	$	2,394
Cumulative stock-based compensation expense related to stock options recorded upon effectiveness of our IPO	—		6,236
Post-IPO stock-based compensation expense related to stock options	1,440		2,025
Stock-based compensation expense related to the issuance of common stock to directors	—		130
Stock-based compensation expense related to restricted stock units	134		134
Total stock-based compensation expense	$	1,574	$	10,919

Stock-based compensation expense for restricted stock units, stock options and issuances of common stock is included in the following line items in the accompanying condensed consolidated statements of operations for the three and nine months ended September 30, 2017 (in thousands):



	Three Months Ended		Nine Months Ended
	September 30, 2017		September 30, 2017
Cost of revenue
Subscriptions, software and support	$	80	$	484
Professional services	142		1,126
Operating expenses
Sales and marketing	359		2,782
Research and development	256		2,458
General and administrative	737		4,069
Total stock-based compensation expense	$	1,574	$	10,919

For the three and nine months ended September 30, 2016, no stock-based compensation expense was recognized for our stock option awards because a qualifying event had not yet occurred.

Convertible Preferred Stock and Stockholders’ Equity (Deficit)

9 Months Ended

Sep. 30, 2017

Equity [Abstract]

Convertible Preferred Stock and Stockholders’ Equity (Deficit)

Convertible Preferred Stock

Immediately prior to the completion of the IPO, all shares of convertible preferred stock then outstanding were automatically converted into 18,163,158 shares of common stock on a one-for-one basis, and then reclassified as shares of Class B common stock.

Summary of Activity

The following tables present a summary of activity for our convertible preferred stock issued and outstanding for the nine months ended September 30, 2017 (dollar amounts in thousands):



	Series A Convertible Preferred Stock					Series B Convertible Preferred Stock
	Amount			Shares		Amount			Shares
Balance as of January 1, 2017	$	17,915		12,043,108		$	37,500		6,120,050
Accretion of dividends on convertible preferred stock	357			—		—			—
Payment of accrued dividend to Series A convertible preferred stockholders	(7,565		)	—		—			—
Conversion of convertible preferred stock to common stock	(10,707		)	(12,043,108	)	(37,500		)	(6,120,050	)
Balance as of September 30, 2017	$	—		—		$	—		—

Common Stock

Immediately prior to the completion of the IPO, all shares of common stock then outstanding were converted into Class B common stock on a one-for-one basis. We offered and sold newly authorized shares of Class A common stock in the IPO.

The rights of the holders of Class A common stock and Class B common stock are identical, except with respect to voting and conversion rights. The holders of Class A common stock are entitled to one vote per share, and the holders of Class B common stock are entitled to ten votes per share, on all matters that are subject to stockholder vote. The holders of Class B common stock also have approval rights for certain corporate actions. Each share of Class B common stock may be converted into one share of Class A common stock at the option of its holder and will be automatically converted into one share of Class A common stock upon transfer thereof, subject to certain exceptions. In addition, upon the date on which the outstanding shares of Class B common stock represent less than 10% of the aggregate voting power of our capital stock, all outstanding shares of Class B common stock shall convert automatically into Class A common stock.

Basic and Diluted Loss per Common Share

9 Months Ended

Sep. 30, 2017

Earnings Per Share [Abstract]

Basic and Diluted Loss per Common Share

We use the two-class method to compute net loss per common share because we have issued securities, other than common stock, that contractually entitle the holders to participate in dividends and earnings. These participating securities include our convertible preferred stock which have non-forfeitable rights to participate in any dividends declared on our common stock. The two-class method requires earnings for the period to be allocated between common stock and participating securities based upon their respective rights to receive distributed and undistributed earnings.

Under the two-class method, for periods with net income, basic net income per common share is computed by dividing the net income attributable to common stockholders by the weighted average number of shares of common stock outstanding during the period. Net income attributable to common stockholders is computed by subtracting from net income the portion of current period earnings that the participating securities would have been entitled to receive pursuant to their dividend rights had all of the period’s earnings been distributed. No such adjustment to earnings is made during periods with a net loss, as the holders of the participating securities have no obligation to fund losses.

Diluted net income (loss) per common share is computed under the two-class method by using the weighted average number of shares of common stock outstanding, plus, for periods with net income attributable to common stockholders, the potential dilutive effects of stock options and warrants. In addition, we analyze the potential dilutive effect of the outstanding participating securities under the “if-converted” method when calculating diluted earnings per share, in which it is assumed that the outstanding participating securities convert into common stock at the beginning of the period or date of issuance, if later. We report the more dilutive of the approaches (two-class or “if-converted”) as our diluted net income per share during the period.

The following securities have been excluded from the calculation of weighted average common shares outstanding because the effect is anti-dilutive or performance or market conditions had not been met at the end of the period:



	Three Months Ended September 30,		Nine Months Ended September 30,
	2017	2016	2017	2016
Convertible preferred stock:
Series A convertible preferred stock	—	12,043,108	—	12,043,108
Series B convertible preferred stock	—	6,120,050	—	6,120,050
Warrant to purchase Series A convertible preferred stock	—	84,360	—	84,360
Stock options	7,383,928	6,699,048	7,383,928	6,699,048
Restricted stock units	42,925	—	42,925	—

Segment and Geographic Information

9 Months Ended

Sep. 30, 2017

Segment Reporting [Abstract]

Segment and Geographic Information

The following table summarizes revenue by geography for the three and nine months ended September 30, 2017 and 2016 (in thousands):



	Three Months Ended September 30,				Nine Months Ended September 30,
	2017		2016		2017		2016
Domestic	$	31,878	$	23,650	$	93,860	$	80,715
International	12,770		7,095		32,315		18,461
Total	$	44,648	$	30,745	$	126,175	$	99,176

With respect to geographic information, revenue is attributed to respective geographies based on the contracting address of the customer. There were no individual foreign countries from which more than 10% of our total revenue was attributable for the three and nine months ended September 30, 2017 and 2016. Substantially all of our long-lived assets were held in the United States as of September 30, 2017 and December 31, 2016.

Subsequent Events	9 Months Ended
Subsequent Events	Sep. 30, 2017
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events In preparing our condensed consolidated financial statements, we evaluated subsequent events through November 2, 2017, which is the date that the condensed consolidated financial statements were available to be issued. In November 2017, we entered into a $20.0 million revolving line of credit with a lender. The facility matures in November 2022. We may elect whether amounts drawn on the revolving line of credit bear interest at a floating rate per annum equal to either the LIBOR or the prime rate plus an additional interest rate margin that is determined by the availability of borrowings under the revolving line of credit. The additional interest rate margin will range from 2.00% to 2.50% in the case of LIBOR advances and from 1.00% to 1.50% in the case of prime rate advances. The revolving line of credit contains an unused facility fee in an amount between 0.15% and 0.25% of the average unused portion of the revolving line of credit, which is payable quarterly. The agreement contains certain customary affirmative and negative covenants and requires us to maintain (i) an adjusted quick ratio of at least 1.35 to 1.0 and (ii) minimum adjusted EBITDA, in the amounts and for the periods set forth in the agreement. Any amounts borrowed under the credit facility are collateralized by substantially all of our assets. On October 25, 2017, our board of directors approved the grant of 689,200 restricted stock units under the 2017 Plan at a fair value of $22.27 per share to members of management and other employees. The value of these awards at the grant date was $15.3 million and will be amortized over the vesting periods. In addition, our board of directors also approved stock option grants under the 2017 Plan to purchase an aggregate of 4,000 shares of common stock at an exercise price of $22.27 per share. The restricted stock units and options vest over five years through October 25, 2022.

Significant Accounting Policies (Policies)

9 Months Ended

Sep. 30, 2017

Accounting Policies [Abstract]

Basis of Presentation

Use of Estimates

Principles of Consolidation

Initial Public Offering

Revenue Recognition

Subscriptions, Software and Support Revenue

SaaS Subscriptions

Term License Subscriptions

Perpetual Licenses

Professional Services

Multiple Element Arrangements

SaaS Subscriptions

Term License Subscriptions

Perpetual Licenses

Deferred Revenue

Cost of Revenue

Cost of Subscriptions, Software and Support Revenue

Cost of Professional Services Revenue

Concentration of Credit Risk

Federal government agencies accounted for 9.1% and 17.2% of accounts receivable at September 30, 2017 and December 31, 2016, respectively.

Accounts Receivable and Allowance for Doubtful Accounts

Deferred Commissions

Fair Value of Financial Instruments


•	Level 1. Observable inputs based on unadjusted quoted prices in active markets for identical assets or liabilities;


•	Level 2. Inputs, other than quoted prices in active markets, that are observable either directly or indirectly; and


•	Level 3. Unobservable inputs for which there is little or no market data, which require us to develop our own assumptions.

Assets and Liabilities Measured at Fair Value on a Recurring Basis

Stock-Based Compensation

Emerging Growth Company Status

Recent Accounting Pronouncements

Adopted

Not Yet Adopted

Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2017

Accounting Policies [Abstract]

Summary of Liabilities Fair Value Measurements

The following table summarizes the conclusions reached as of December 31, 2016 (in thousands):



	December 31, 2016		Level 1		Level 2		Level 3
Liabilities:
Series A convertible preferred stock warrant(1)	$	850	$	—	$	—	$	850
	$	850	$	—	$	—	$	850

_______________________________________________

(1)

Summary of Changes in Level 3 Instruments Measured at Fair Value On Recurring Basis

The following table presents the changes in our Level 3 instruments measured at fair value on a recurring basis during the nine months ended September 30, 2017 and 2016 (in thousands):



	Nine Months Ended September 30,
	2017			2016
Balance as of January 1	$	850		$	650
Change in fair value of warrant liability	341			200
Reclassification of warrant liability to equity	(1,191		)	—
Balance as of September 30	$	—		$	850

Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2017

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Summary of Assumptions Used to Estimate the Fair Value of Stock Options Granted

The following table summarizes the assumptions used to estimate the fair value of stock options granted during the three and nine months ended September 30, 2017 and 2016:



	Three Months Ended September 30,		Nine Months Ended September 30,
	2017	2016	2017	2016
Risk-free interest rate	1.9% - 2.1%	1.3%	1.9% - 2.2%	1.3% - 1.5%
Expected term (in years)	6.5	6.5	6.5	6.5
Expected volatility	38.6%	41.6%	38.6% - 40.6%	41.2% - 42.0%
Expected dividend yield	—%	—%	—%	—%

Summary of the Stock Option Activity

The following table summarizes the stock option activity for the nine months ended September 30, 2017:



	Number of Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value (in thousands)
Outstanding at January 1, 2017	6,784,448		$	4.65	6.5	$	44,259
Granted	1,252,200		11.89
Exercised	(556,220	)	1.19			8,386
Canceled	(96,500	)	6.30
Outstanding at September 30, 2017	7,383,928		6.16		6.7	164,688
Exercisable at September 30, 2017	2,992,648		1.85		3.8	79,636

Schedule of Restricted Stock Unit Activity

The following table summarizes the restricted stock unit activity for the nine months ended September 30, 2017:



	Number of Shares		Weighted Average Grant Date Fair Value
Non-vested outstanding at December 31, 2016	—		$	—
Granted	47,855		20.38
Vested	(4,930	)	20.24
Canceled	—		—
Non-vested outstanding at September 30, 2017	42,925		20.40

Schedule of Components of Stock-based Compensation Expense

The following table summarizes the components of our stock-based compensation expense for the three and nine months ended September 30, 2017 (in thousands):



	Three Months Ended		Nine Months Ended
	September 30, 2017		September 30, 2017
Stock-based compensation expense related to stock option modifications	$	—	$	2,394
Cumulative stock-based compensation expense related to stock options recorded upon effectiveness of our IPO	—		6,236
Post-IPO stock-based compensation expense related to stock options	1,440		2,025
Stock-based compensation expense related to the issuance of common stock to directors	—		130
Stock-based compensation expense related to restricted stock units	134		134
Total stock-based compensation expense	$	1,574	$	10,919

Schedule of Stock-based Compensation Expense Included in Condensed Consolidated Statements of Operations



	Three Months Ended		Nine Months Ended
	September 30, 2017		September 30, 2017
Cost of revenue
Subscriptions, software and support	$	80	$	484
Professional services	142		1,126
Operating expenses
Sales and marketing	359		2,782
Research and development	256		2,458
General and administrative	737		4,069
Total stock-based compensation expense	$	1,574	$	10,919

Convertible Preferred Stock and Stockholders’ Equity (Deficit) (Tables)

9 Months Ended

Sep. 30, 2017

Equity [Abstract]

Summary of Activity for Convertible Preferred Stock Issued and Outstanding

The following tables present a summary of activity for our convertible preferred stock issued and outstanding for the nine months ended September 30, 2017 (dollar amounts in thousands):



	Series A Convertible Preferred Stock					Series B Convertible Preferred Stock
	Amount			Shares		Amount			Shares
Balance as of January 1, 2017	$	17,915		12,043,108		$	37,500		6,120,050
Accretion of dividends on convertible preferred stock	357			—		—			—
Payment of accrued dividend to Series A convertible preferred stockholders	(7,565		)	—		—			—
Conversion of convertible preferred stock to common stock	(10,707		)	(12,043,108	)	(37,500		)	(6,120,050	)
Balance as of September 30, 2017	$	—		—		$	—		—

Basic and Diluted Loss per Common Share (Tables)

9 Months Ended

Sep. 30, 2017

Earnings Per Share [Abstract]

Summary of Securities Excluded From Calculation of Weighted Average Common Shares



	Three Months Ended September 30,		Nine Months Ended September 30,
	2017	2016	2017	2016
Convertible preferred stock:
Series A convertible preferred stock	—	12,043,108	—	12,043,108
Series B convertible preferred stock	—	6,120,050	—	6,120,050
Warrant to purchase Series A convertible preferred stock	—	84,360	—	84,360
Stock options	7,383,928	6,699,048	7,383,928	6,699,048
Restricted stock units	42,925	—	42,925	—

Segment and Geographic Information (Tables)

9 Months Ended

Sep. 30, 2017

Segment Reporting [Abstract]

Summary of Revenue By Geography

The following table summarizes revenue by geography for the three and nine months ended September 30, 2017 and 2016 (in thousands):



	Three Months Ended September 30,				Nine Months Ended September 30,
	2017		2016		2017		2016
Domestic	$	31,878	$	23,650	$	93,860	$	80,715
International	12,770		7,095		32,315		18,461
Total	$	44,648	$	30,745	$	126,175	$	99,176

Significant Accounting Policies - Additional Information (Details)	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	May 31, 2017 USD ($) $ / shares shares	Sep. 30, 2017 USD ($) agency	Sep. 30, 2016 USD ($) agency	Sep. 30, 2017 USD ($) agency	Sep. 30, 2016 USD ($) agency	Dec. 31, 2016 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Net proceeds from initial public offering				$ 80,213,000	$ 0
Deferred offering costs		$ 2,400,000		$ 2,400,000
Percentage of license revenue		1.00%	1.00%	1.00%	1.00%
Change in allowance for doubtful accounts				$ 0		$ 0
Commission expense		$ 3,200,000	$ 1,800,000	$ 8,500,000	$ 5,400,000
Customer Concentration Risk \| Sales Revenue, Net \| Foreign Customers
Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage		28.60%	23.10%	25.60%	18.60%
Customer Concentration Risk \| Sales Revenue, Net \| Government Agencies
Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage		14.20%	19.40%	15.40%	28.50%
Customer Concentration Risk \| Sales Revenue, Net \| Federal Government Agencies
Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage		7.70%	13.10%	9.10%	19.50%
Number of federal government agencies \| agency		3	3	3	3
Customer Concentration Risk \| Accounts Receivable \| Federal Government Agencies
Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage				9.10%		17.20%
Minimum
Summary Of Significant Accounting Policies [Line Items]
SaaS Subscriptions contracts term				1 year
Term license subscription contracts term				1 year
Maximum
Summary Of Significant Accounting Policies [Line Items]
SaaS Subscriptions contracts term				5 years
Term license subscription contracts term				5 years
Class A Common Stock
Summary Of Significant Accounting Policies [Line Items]
Net proceeds from initial public offering	$ 77,800,000
Class B Common Stock
Summary Of Significant Accounting Policies [Line Items]
Preferred stock conversion basis				1
IPO \| Class A Common Stock
Summary Of Significant Accounting Policies [Line Items]
Issuance of common stock from initial public offering, net of issuance costs, Shares \| shares	7,187,500
Shares issued price per share \| $ / shares	$ 12.00

Significant Accounting Policies - Summary of Liabilities Fair Value Measurements (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurements, Liabilities		$ 850
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurements, Liabilities	$ 0	850	$ 850	$ 650
Series A Convertible Preferred Stock Warrant
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurements, Liabilities		850
Series A Convertible Preferred Stock Warrant \| Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurements, Liabilities		$ 850

Significant Accounting Policies - Summary of Changes in Level 3 Instruments Measured at Fair Value On Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of January 1	$ 850
Level 3
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of January 1	850	$ 650
Change in fair value of warrant liability	341	200
Reclassification of warrant liability to equity	(1,191)	0
Balance as of September 30	$ 0	$ 850

Accrued Expenses - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Payables and Accruals [Abstract]
Accrued contract labor costs	$ 3,122	$ 743
Accrued audit and tax expenses	364	358
Accrued reimbursable employee expenses	285	134
Accrued marketing and tradeshow expenses	251	111
Other accrued expenses	1,955	1,514
Total	$ 5,977	$ 2,860

Debt - Additional Information (Detail) - USD ($)	9 Months Ended
Debt - Additional Information (Detail) - USD ($)	Sep. 30, 2017	Sep. 30, 2016	Apr. 30, 2017	Jan. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Line of Credit Facility [Line Items]
Loss on extinguishment of debt	$ 384,000	$ 0
Revolving Credit Facility
Line of Credit Facility [Line Items]
Credit facility	20,000,000		$ 5,000,000		$ 10,000,000
Term Loan
Line of Credit Facility [Line Items]
Credit facility			20,000,000	$ 20,000,000		$ 10,000,000
Line of credit, outstanding borrowings	0
Term Loan \| Other (Income) Expense
Line of Credit Facility [Line Items]
Loss on extinguishment of debt	$ 400,000
Subordinated Term Loan
Line of Credit Facility [Line Items]
Credit facility			$ 10,000,000

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References + Details

Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Taxes [Line Items]
Effective tax rate	(3.10%)	25.40%	(2.10%)	20.30%
Net unrecognized tax benefits which would impact effective tax rate if recognized	$ 0.5		$ 0.5
Earliest Tax Year
Income Taxes [Line Items]
Open tax year			2013
Latest Tax Year
Income Taxes [Line Items]
Open tax year			2016
Minimum \| Subsidiaries
Income Taxes [Line Items]
Effective tax rate			0.00%
Maximum \| Subsidiaries
Income Taxes [Line Items]
Effective tax rate			40.00%

Stock-Based Compensation - Additional Information (Detail) - USD ($)		1 Months Ended	3 Months Ended	9 Months Ended
	Apr. 25, 2017	May 31, 2017	Sep. 30, 2017	Sep. 30, 2017	Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period for option exercise				5 years
Stock-based compensation expense			$ 1,574,000	$ 10,919,000
Granted				$ 5.04	$ 4.38
Vested				$ 5,300,000	$ 0
Compensation cost related to nonvested stock options not yet recognized			12,600,000	$ 12,600,000
Unrecognized compensation cost related to nonvested stock option recognized over weighted average period, in years				3 years
Aggregate purchase of stock options	216,160
Cumulative Stock-based Compensation Expense Related to Stock Options Recorded upon Effectiveness of Our IPO
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense			0	$ 6,236,000
Cumulative Stock-based Compensation Expense Related to Stock Options Recorded upon Effectiveness of Our IPO \| Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense		$ 6,200,000
Stock Option Modifications
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 2,400,000		$ 0	$ 2,394,000
2017 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available to be issued			6,425,767	6,425,767
2017 Equity Incentive Plan \| Class A Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available to be issued		6,421,442	6,481,622	6,481,622
2007 Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available to be issued		421,442
Number of shares available for grants		0
Period for which options can be granted				10 years

Stock-Based Compensation - Summary of Estimate the Fair Value of Stock Options Granted (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Share-based Goods and Nonemployee Services Transaction [Line Items]
Risk-free interest rate		1.30%
Expected term (in years)	6 years 6 months	6 years 6 months	6 years 6 months	6 years 6 months
Expected volatility	38.60%	41.60%
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Minimum
Share-based Goods and Nonemployee Services Transaction [Line Items]
Risk-free interest rate	1.90%		1.90%	1.30%
Expected volatility			38.60%	41.20%
Maximum
Share-based Goods and Nonemployee Services Transaction [Line Items]
Risk-free interest rate	2.10%		2.20%	1.50%
Expected volatility			40.60%	42.00%

Stock-Based Compensation - Summary of the Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Number of Shares
January 1, 2017	6,784,448
Granted	1,252,200
Exercised	(556,220)
Canceled	(96,500)
September 30, 2017	7,383,928	6,784,448
September 30, 2017	2,992,648
Weighted Average Exercise Price
January 1, 2017	$ 4.65
Granted	11.89
Exercised	1.19
Canceled	6.30
September 30, 2017	6.16	$ 4.65
September 30, 2017	$ 1.85
Weighted Average Remaining Contractual Term (Years)
January 1, 2017	6 years 8 months 12 days	6 years 6 months
September 30, 2017	6 years 8 months 12 days	6 years 6 months
September 30, 2017	3 years 9 months 18 days
Aggregate Intrinsic Value (in thousands)
January 1, 2017	$ 44,259
Exercised	8,386
September 30, 2017	164,688	$ 44,259
September 30, 2017	$ 79,636

Stock-Based Compensation - Schedule of Restricted Stock Unit Activity (Details) - Restricted Stock Units $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2017 USD ($) $ / shares shares
Number of Shares
Non-vested outstanding at December 31, 2016 \| shares	0
Granted \| shares	47,855
Vested \| shares	(4,930)
Canceled \| shares	0
Non-vested outstanding at September 30, 2017 \| shares	42,925.000
Weighted Average Grant Date Fair Value
Non-vested outstanding at December 31, 2016 \| $ / shares	$ 0.00
Granted \| $ / shares	20.38
Vested \| $ / shares	20.24
Canceled \| $ / shares	0.00
Non-vested outstanding at September 30, 2017 \| $ / shares	$ 20.40
Total unrecognized compensation cost related to unvested restricted stock units \| $	$ 0.8
Weighted average remaining vesting period	2 years 8 months 12 days

Stock-Based Compensation - Schedule of Stock-based Compensation Expense (Detail) - USD ($) $ in Thousands		3 Months Ended	9 Months Ended
	Apr. 25, 2017	Sep. 30, 2017	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense		$ 1,574	$ 10,919
Stock Option Modifications
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 2,400	0	2,394
Cumulative Stock-based Compensation Expense Related to Stock Options Recorded upon Effectiveness of Our IPO
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense		0	6,236
Post-IPO Stock-based Compensation Expense Related to Stock Options
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense		1,440	2,025
Stock-based Compensation Expense Related to the Issuance of Common Stock to Directors
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense		0	130
Stock-based Compensation Expense Related to Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense		$ 134	$ 134

Stock-Based Compensation - Schedule of Stock-based Compensation Expense Included in Condensed Consolidated Statements of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 1,574	$ 10,919
Subscriptions, software and support
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	80	484
Professional services
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	142	1,126
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	359	2,782
Research and development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	256	2,458
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 737	$ 4,069

Convertible Preferred Stock and Stockholders' Equity (Deficit) - Additional Information (Detail)		9 Months Ended
	May 24, 2017 shares	Sep. 30, 2017 vote shares
Temporary Equity [Line Items]
Convertible preferred stock outstanding shares converted into common stock		1
Class B Common Stock
Temporary Equity [Line Items]
Conversion of convertible preferred stock to common stock (in shares)	18,163,158
Convertible preferred stock outstanding shares converted into common stock		1
Preferred stock conversion basis		1
Number of votes entitled to stockholders \| vote		10
Class A Common Stock
Temporary Equity [Line Items]
Number of votes entitled to stockholders \| vote		1
Conversion of stock (in shares)		1
Maximum percentage of aggregate voting power of capital stock which triggers conversion of stock		10.00%

Convertible Preferred Stock and Stockholders' Equity (Deficit) - Summary of Activity for Convertible Preferred Stock Issued and Outstanding (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Increase (Decrease) in Temporary Equity [Roll Forward]
Payment of accrued dividend to Series A convertible preferred stockholders	$ (7,565)	$ 0
Series A Convertible Preferred Stock
Increase (Decrease) in Temporary Equity [Roll Forward]
Beginning balance, January 1, 2017	$ 17,915
Beginning balance, shares issued	12,043,108
Accretion of dividends on convertible preferred stock	$ 357
Payment of accrued dividend to Series A convertible preferred stockholders	$ (7,565)
Conversion of convertible preferred stock to common stock (in shares)	(12,043,108)
Conversion of convertible preferred stock to common stock	$ (10,707)
Ending balance, September 30, 2017	$ 0
Ending balance, shares issued	0
Series B Convertible Preferred Stock
Increase (Decrease) in Temporary Equity [Roll Forward]
Beginning balance, January 1, 2017	$ 37,500
Beginning balance, shares issued	6,120,050
Accretion of dividends on convertible preferred stock	$ 0
Payment of accrued dividend to Series A convertible preferred stockholders	$ 0
Conversion of convertible preferred stock to common stock (in shares)	(6,120,050)
Conversion of convertible preferred stock to common stock	$ (37,500)
Ending balance, September 30, 2017	$ 0
Ending balance, shares issued	0

Warrants - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	Sep. 30, 2017	May 31, 2017
Class of Warrant or Right [Line Items]
Warrant exercise price (in dollars per share)	$ 0.88905
Warrant
Class of Warrant or Right [Line Items]
Fair value of warrant	$ 1.2
Series A Convertible Preferred Stock
Class of Warrant or Right [Line Items]
Warrant to purchase shares of preferred stock (in shares)	84,360
Class B Common Stock
Class of Warrant or Right [Line Items]
Shares issued on cashless exercise of warrants (in shares)		79,363
Class B Common Stock \| Prior to IPO
Class of Warrant or Right [Line Items]
Warrant to purchase shares of preferred stock (in shares)	84,360

Basic and Diluted Loss per Common Share - Summary of Securities Excluded From Calculation of Weighted Average Common Shares Outstanding (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Series A Convertible Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Convertible preferred stock (in shares)	0	12,043,108	0	12,043,108
Series B Convertible Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Convertible preferred stock (in shares)	0	6,120,050	0	6,120,050
Warrant To Purchase Series A Convertible Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Convertible preferred stock (in shares)	0	84,360	0	84,360
Employee Stock Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Convertible preferred stock (in shares)	7,383,928	6,699,048	7,383,928	6,699,048
Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Convertible preferred stock (in shares)	42,925	0	42,925	0

Segment and Geographic Information - Summary of Revenues By Geography (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 44,648	$ 30,745	$ 126,175	$ 99,176
Domestic
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	31,878	23,650	93,860	80,715
International
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 12,770	$ 7,095	$ 32,315	$ 18,461

Segment and Geographic Information - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Sales Revenue, Net \| Geographic Concentration Risk
Segment Reporting Information [Line Items]
Concentration risk, percentage	10.00%	10.00%	10.00%	10.00%

Subsequent Events (Details) - USD ($)			9 Months Ended
Subsequent Events (Details) - USD ($)	Nov. 02, 2017	Oct. 25, 2017	Sep. 30, 2017
Subsequent Event [Line Items]
Granted			1,252,200
Granted			$ 11.89
Revolving Credit Facility \| Subsequent Event
Subsequent Event [Line Items]
Credit facility	$ 20,000,000.0
Quick ratio	135.00%
Minimum \| Revolving Credit Facility \| Subsequent Event
Subsequent Event [Line Items]
Unused credit facility fee	0.15%
Maximum \| Revolving Credit Facility \| Subsequent Event
Subsequent Event [Line Items]
Unused credit facility fee	0.25%
London Interbank Offered Rate (LIBOR) \| Minimum \| Revolving Credit Facility \| Subsequent Event
Subsequent Event [Line Items]
Interest rate margin	2.00%
London Interbank Offered Rate (LIBOR) \| Maximum \| Revolving Credit Facility \| Subsequent Event
Subsequent Event [Line Items]
Interest rate margin	2.50%
Prime Rate \| Minimum \| Revolving Credit Facility \| Subsequent Event
Subsequent Event [Line Items]
Interest rate margin	1.00%
Prime Rate \| Maximum \| Revolving Credit Facility \| Subsequent Event
Subsequent Event [Line Items]
Interest rate margin	1.50%
Restricted Stock Units
Subsequent Event [Line Items]
Granted			$ 20.38
2017 Equity Incentive Plan \| Subsequent Event
Subsequent Event [Line Items]
Vesting period		5 years
2017 Equity Incentive Plan \| Restricted Stock Units \| Subsequent Event
Subsequent Event [Line Items]
Restricted stock units, granted		689,200
Granted		$ 22.27
Value of awards, at grant date		$ 15,300,000
2017 Equity Incentive Plan \| Common Stock \| Subsequent Event
Subsequent Event [Line Items]
Granted		4,000
Granted		$ 22.27

Warrants	9 Months Ended
Warrants	Sep. 30, 2017
Warrants and Rights Note Disclosure [Abstract]
Warrants	Warrants We previously issued a warrant to purchase 84,360 shares of Series A convertible preferred stock in conjunction with a credit facility with a lender at an exercise price of $0.88905 per share. Immediately prior to the completion of the IPO, this warrant was converted into a warrant to purchase 84,360 shares of Class B common stock. The fair value at the time of the conversion was $1.2 million and was recorded as additional paid-in capital and a reduction of the preferred stock warrant liability. In May 2017, the warrant holder exercised the warrant and we issued 79,363 shares of Class B common stock through a cashless exercise of the warrant, in accordance with its terms.