RingCentral (RNG) 10-K 28 Feb 17 2016 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2016	Feb. 23, 2017	Jun. 30, 2016
Document And Entity Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	FY
Trading Symbol	RNG
Entity Registrant Name	RingCentral Inc
Entity Central Index Key	1,384,905
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 1.2
Class A common stock
Document And Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		61,436,671
Class B common stock
Document And Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		13,089,918

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets
Cash and cash equivalents	$ 160,355	$ 137,588
Accounts receivable, net	30,243	19,163
Inventory	63	2,317
Prepaid expenses and other current assets	15,250	11,978
Total current assets	205,911	171,046
Property and equipment, net	31,994	28,160
Goodwill	9,393	9,393
Acquired intangibles, net	2,244	3,266
Other assets	3,087	2,948
Total assets	252,629	214,813
Current liabilities
Accounts payable	7,810	5,196
Accrued liabilities	48,322	34,702
Current portion of capital lease obligation	181	269
Current portion of long-term debt	14,528	3,750
Deferred revenue	45,159	36,657
Total current liabilities	116,000	80,574
Long-term debt	312	14,840
Sales tax liability	3,077	3,670
Capital lease obligation		181
Other long-term liabilities	3,199	5,416
Total liabilities	122,588	104,681
Commitments and contingencies (Note 8)
Stockholders' equity:
Additional paid-in capital	366,800	319,792
Accumulated other comprehensive income	2,737	527
Accumulated deficit	(239,503)	(210,194)
Total stockholders' equity	130,041	110,132
Total liabilities and stockholders' equity	252,629	214,813
Class A common stock
Stockholders' equity:
Common stock	6	6
Class B common stock
Stockholders' equity:
Common stock	$ 1	$ 1

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2016	Dec. 31, 2015
Class A common stock
Common stock, par or stated value per share	$ 0.0001	$ 0.0001
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	61,292,000	58,480,000
Common stock, shares outstanding	61,292,000	58,480,000
Class B common stock
Common stock, par or stated value per share	$ 0.0001	$ 0.0001
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	13,091,000	13,483,000
Common stock, shares outstanding	13,091,000	13,483,000

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues
Software subscriptions	$ 355,850	$ 271,245	$ 200,098
Other	23,874	24,983	19,789
Total revenues	379,724	296,228	219,887
Cost of revenues
Software subscriptions	73,470	66,354	58,673
Other	18,741	20,917	18,100
Total cost of revenues	92,211	87,271	76,773
Gross profit	287,513	208,957	143,114
Operating expenses
Research and development	65,514	52,924	44,582
Sales and marketing	192,497	139,851	104,827
General and administrative	55,454	47,114	38,910
Total operating expenses	313,465	239,889	188,319
Loss from operations	(25,952)	(30,932)	(45,205)
Other income (expense), net
Interest expense	(746)	(1,123)	(2,007)
Other income (expense), net	(2,375)	(1,307)	(1,031)
Other income (expense), net	(3,121)	(2,430)	(3,038)
Loss before provision (benefit) for income taxes	(29,073)	(33,362)	(48,243)
Provision (benefit) for income taxes	236	(1,263)	97
Net loss	$ (29,309)	$ (32,099)	$ (48,340)
Net loss per common share
Basic and diluted	$ (0.40)	$ (0.46)	$ (0.72)
Weighted-average number of shares used in computing net loss per share
Basic and diluted	72,994	70,069	66,818

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (29,309)	$ (32,099)	$ (48,340)
Other comprehensive income/(loss)
Foreign currency translation adjustments, net	2,210	561	276
Unrealized gain (loss) on available-for-sale securities		217	(217)
Comprehensive loss	$ (27,099)	$ (31,321)	$ (48,281)

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Glip, Inc.	Common Stock	Common StockGlip, Inc.	Additional Paid-in Capital	Additional Paid-in CapitalGlip, Inc.	Accumulated Other Comprehensive Loss	Accumulated Deficit
Beginning Balance at Dec. 31, 2013	$ 63,515		$ 6		$ 193,574		$ (310)	$ (129,755)
Beginning Balance, shares at Dec. 31, 2013			62,244
Issuance of common stock in connection with Secondary Offering (net of issuance of costs of $1,050)	56,117				56,117
Issuance of common stock in connection with Secondary Offering (net of issuance of costs of $1,050), shares			2,792
Issuance of common stock in connection with Equity Incentive and Employee Stock Purchase plans	9,638		$ 1		9,637
Issuance of common stock in connection with Equity Incentive and Employee Stock Purchase plans, shares			3,523
Share-based compensation	15,516				15,516
Changes in comprehensive loss	59						59
Net loss	(48,340)							(48,340)
Ending Balance at Dec. 31, 2014	96,505		$ 7		274,844		(251)	(178,095)
Ending Balance, shares at Dec. 31, 2014			68,559
Issuance of common stock in connection with Equity Incentive and Employee Stock Purchase plans	19,413				19,413
Issuance of common stock in connection with Equity Incentive and Employee Stock Purchase plans, shares			3,181
Issuance of shares of business acquisition	3,447				3,447
Issuance of shares of business acquisition, shares			223
Share-based compensation	22,088				22,088
Changes in comprehensive loss	778						778
Net loss	(32,099)							(32,099)
Ending Balance at Dec. 31, 2015	110,132		$ 7		319,792		527	(210,194)
Ending Balance, shares at Dec. 31, 2015			71,963
Issuance of common stock in connection with Equity Incentive and Employee Stock Purchase plans	14,849				14,849
Issuance of common stock in connection with Equity Incentive and Employee Stock Purchase plans, shares			2,374
Issuance of shares of business acquisition		$ 1,080				$ 1,080
Issuance of shares of business acquisition, shares				46
Share-based compensation	31,079				31,079
Changes in comprehensive loss	2,210						2,210
Net loss	(29,309)							(29,309)
Ending Balance at Dec. 31, 2016	$ 130,041		$ 7		$ 366,800		$ 2,737	$ (239,503)
Ending Balance, shares at Dec. 31, 2016			71,963

CONSOLIDATED STATEMENTS OF STO7

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2014USD ($)
Common Stock
Issuance costs	$ 1,050

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities
Net loss	$ (29,309)	$ (32,099)	$ (48,340)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities
Depreciation and amortization	14,663	13,467	10,378
Share-based compensation	30,840	22,088	15,516
Foreign currency remeasurement loss	2,615	843	648
Tax benefit from release of valuation allowance		(1,411)
Impairment of fixed assets		1,317
Non-cash interest and other expense related to debt		156	259
Net accretion of discount and amortization of premium on available-for-sale securities		616
Provision for bad debt	648	411	40
Deferred income tax	(36)	(8)	(35)
Others	583	416	100
Changes in assets and liabilities
Accounts receivable	(11,728)	(11,923)	(4,646)
Inventory	2,254	(606)	401
Prepaid expenses and other current assets	(3,272)	(3,636)	(3,553)
Other assets	76	(422)	(1,660)
Accounts payable	1,516	1,591	(510)
Accrued liabilities	15,165	2,354	9,054
Deferred revenue	8,502	11,071	9,034
Other liabilities	(2,809)	861	1,884
Net cash provided by (used in) operating activities	29,708	5,086	(11,430)
Cash flows from investing activities
Purchases of property and equipment	(14,236)	(14,631)	(17,267)
Capitalized internal-use software	(2,162)	(2,513)	(698)
Cash paid for business combination, net of cash acquired		(4,670)
Restricted investments		100
Proceeds from the maturity of available-for-sale securities		28,080
Purchases of available-for-sale securities			(28,696)
Net cash provided by (used in) investing activities	(16,398)	6,366	(46,661)
Cash flows from financing activities
Proceeds from issuance of stock in connection with stock plans	15,104	19,524	9,487
Payment of holdback from Glip acquisition	(1,500)
Repayment of debt	(3,750)	(6,142)	(9,909)
Repayment of capital lease obligations	(269)	(594)	(698)
Taxes paid related to net share settlement of equity awards	(255)	(151)	(41)
Net proceeds from public offerings of common stock			57,167
Payment of offering costs			(1,219)
Net cash provided by financing activities	9,330	12,637	54,787
Effect of exchange rate changes on cash and cash equivalents	127	317	108
Net increase (decrease) in cash and cash equivalents	22,767	24,406	(3,196)
Cash and cash equivalents
Beginning of period	137,588	113,182	116,378
End of period	160,355	137,588	113,182
Supplemental disclosure of cash flow data
Cash paid for interest	711	1,893	1,267
Cash paid for income taxes	229	100	96
Non-cash investing and financing activities
Issuance of common stock for business combination		3,447
Change in liability for unvested exercised options	3	38	47
Equipment and capitalized internal-use software purchased and unpaid at period end	2,152	719	1,013
Change in unrealized gain (loss) on available-for-sale securities		$ 217	(217)
Equipment acquired under capital lease			$ 1,149
Glip, Inc.
Non-cash investing and financing activities
Issuance of common stock for business combination	$ 1,080

Description of Business and Sum

Description of Business and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Description of Business and Summary of Significant Accounting Policies	Note 1. Description of Business and Summary of Significant Accounting Policies Description of Business RingCentral, Inc. (the Company) is a provider of software-as-a-service (SaaS) solutions for business communications and collaboration. The Company was incorporated in California in 1999 and was reincorporated in Delaware on September 26, 2014. Public Offerings On October 2, 2013, the Company completed an initial public offering (IPO) and sold 8,625,000 shares of Class A common stock to the public, including the underwriters’ overallotment option of 1,125,000 shares of Class A common stock and 80,000 shares of Class A common stock sold by selling stockholders, at a price of $13.00 per share. The offer and sale of all of the shares in the IPO were registered under the Securities Act pursuant to a registration statement on Form S-1 (File No. 333-190815) (the Initial Registration Statement). The Company received aggregate proceeds of $103.3 million from the IPO, net of underwriters’ discounts and commissions, but before deduction of offering expenses of approximately $3.9 million. On March 11, 2014, the Company completed a secondary public offering and sold 7,991,551 shares of Class A common stock to the public, including 791,551 of the underwriters’ overallotment option and 5,200,000 shares of Class A common stock sold by selling stockholders, at a price of $21.50 per share. The offer and sale of all of the shares in the secondary public offering were registered under the Securities Act pursuant to a registration statement on Form S-1 (File No. 333-194132) (Secondary Registration Statement). The Company received aggregate proceeds of $57.2 million from the secondary public offering, net of underwriters’ discounts and commissions, but before deduction of offering expenses of approximately $1.1 million. The Company did not receive any proceeds from the sale of shares by the selling stockholders. Principles of Consolidation The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) and include the consolidated accounts of the Company and its wholly-owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. The significant estimates made by management affect revenues, the allowance for doubtful accounts, inventory reserves, goodwill, share-based compensation, capitalization of internally developed software, return reserves, provision for income taxes, uncertain tax positions, loss contingencies, sales tax liabilities and accrued liabilities. Management periodically evaluates these estimates and will make adjustments prospectively based upon the results of such periodic evaluations. Actual results could differ from these estimates. Foreign Currency The functional currency of the Company’s foreign subsidiaries is generally the local currency. Adjustments resulting from translating foreign functional currency financial statements into U.S. dollars are recorded as part of a separate component of stockholders’ equity and reported in the statements of comprehensive loss. Foreign currency transaction gains and losses are included in net loss for the period. All assets and liabilities denominated in a foreign currency are translated into U.S. dollars at the exchange rate on the balance sheet date. Revenues and expenses are translated at the average exchange rate during the period. Equity transactions are translated using historical exchange rates. Cash and Cash Equivalents The Company considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. Cash and cash equivalents are stated at fair value. Allowance for Doubtful Accounts For the years ended December 31, 2016 and 2015, a significant portion of revenues were realized from credit card transactions while the remaining revenues generated accounts receivable. The Company determines provisions based on historical loss patterns, the number of days that billings are past due, and an evaluation of the potential risk of loss associated with delinquent accounts. Below is a summary of the changes in allowance for doubtful accounts for the years ended December 31, 2016, 2015 and 2014 (in thousands): Balance at beginning of year Provision, net of recoveries Write-offs Balance at end of year Year ended December 31, 2016 Allowance for doubtful accounts $ 377 $ 648 $ 591 $ 434 Year ended December 31, 2015 Allowance for doubtful accounts $ 125 $ 411 $ 159 $ 377 Year ended December 31, 2014 Allowance for doubtful accounts $ 139 $ 40 $ 54 $ 125 Inventory The Company’s inventory consists primarily of phones held at third parties. Inventory is stated at the lower of cost computed on a first-in, first-out basis, or market value. Inventory write-downs are recorded when the cost of inventory exceeds its net realizable value and establishes a new cost basis for the inventory. On a quarterly and annual basis, the Company analyzes inventory on a part by part basis in comparison to forecasted demand to identify potential excess and obsolescence issues, and adjusts carrying amounts to estimated net realizable value accordingly. Internal-Use Software Development Costs The Company capitalizes qualifying internal-use software development costs that are incurred during the application development stage, provided that management with the relevant authority authorizes and commits to the funding of the project, it is probable the project will be completed, and the software will be used to perform the function intended. Costs related to preliminary project activities and post implementation activities are expensed as incurred. Capitalized internal-use software development costs are included in property and equipment and are amortized on a straight-line basis over their estimated useful lives. For the years ended December 31, 2016 and 2015, the Company capitalized $2.5 million and $2.1 million, net of impairment, of internal-use software development costs, respectively. The carrying value of internal-use software development costs was $4.4 million and $2.6 million at December 31, 2016 and 2015, respectively. Property and Equipment, net Property and equipment, net is stated at cost, less accumulated depreciation and amortization. Depreciation and amortization is calculated on a straight-line basis over the estimated useful lives of those assets as follows: Computer hardware and software 3 to 5 years Internal-use software development costs 3 to 4 years Furniture and fixtures 1 to 5 years Leasehold improvements Shorter of the estimated lease term or useful life The Company evaluates the recoverability of property and equipment for possible impairment whenever events or circumstances indicate that the carrying amount of such assets or asset groups may not be recoverable. Recoverability of these assets or asset groups is measured by comparing the carrying amounts of such assets or asset groups to the future undiscounted cash flows that such assets or asset groups are expected to generate. If this evaluation indicates that the carrying amount of the assets or asset groups is not recoverable, the carrying amount of such assets or asset groups is reduced to its estimated fair value. Maintenance and repairs are charged to expense as incurred. Concentrations of Credit Risk and Significant Customers Financial instruments that subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents and accounts receivable. Although the Company deposits its cash with multiple financial institutions, its deposits, at times, may exceed federally insured limits. The Company’s accounts receivable are primarily derived from sales by resellers and to larger direct customers. The Company performs ongoing credit evaluations of its resellers and does not require collateral on accounts receivable. The Company maintains an allowance for doubtful accounts for estimated potential credit losses. At December 31, 2016 and 2015, AT&T, one of our resellers, accounted for 30% and 39% of the Company’s total accounts receivable, respectively. For the years ended December 31, 2016, 2015, and 2014, AT&T accounted for 14%, 13%, and 12% of the Company’s total revenues and 13%, 12%, and 11% of the Company’s software subscription revenues, respectively. During the years ended December 31, 2016, 2015 and 2014, the Company contracted a significant portion of its software development efforts from third-party vendors located in Russia and Ukraine. A cessation of services provided by these vendors could result in a disruption to the Company’s research and development efforts. Revenue Recognition The Company’s revenues consist primarily of software subscriptions and other revenues. The Company’s software subscriptions revenue includes all fees billed in connection with subscriptions to the Company’s RingCentral Office, RingCentral Professional, RingCentral Fax, RingCentral Contact Center, and RingCentral Glip products. These software subscription fees include recurring fixed plan subscription fees, variable usage-based fees for usage in excess of plan limits, recurring administrative cost recovery fees, one-time fees, and other recurring fees related to our subscriptions. The Company provides its subscriptions pursuant to contractual arrangements that range in duration from one month to three years. The Company’s subscription fees are generally billed in advance directly to customer credit cards or via invoices issued to larger customers. The Company’s other revenues consist of commission revenues earned as an agent of Westcon, product revenues from sales of phones not sold under the sales agency agreement with Westcon, phone sales to carrier partners, phone rentals, and professional implementation services. The Company recognizes revenue when the following criteria are met: • there is persuasive evidence of an arrangement; • the subscription is being provided to the customer or the product has been delivered; • the amount of fees to be paid by the customer is fixed or determinable; and • the collection of the fees is reasonably assured. Revenue under subscription plans are recognized as follows: • fixed plan subscription and administrative cost recovery fees are recognized on a straight-line basis over their respective contractual subscription terms; • fees for additional minutes of usage in excess of plan limits are recognized over the estimated usage period in a manner that approximates actual usage; and • one-time upfront fees are initially deferred and recognized on a straight-line basis over the estimated average customer life. Commission revenue is recognized when services have been rendered. Product revenue is billed at the time the order is received and recognized when the phone has been delivered to the customer. Professional service revenue is recognized upon completion of performance. The Company enters into arrangements with multiple-elements that generally include services to be provided under the subscription plan and the sale of products used in connection with the Company’s subscriptions. The Company allocates the consideration to each deliverable in a multiple-deliverable arrangement based upon its relative selling prices. The Company determines the selling price using vendor-specific objective evidence (VSOE) for its subscription plans and best estimated selling price (BESP) for its product offerings. Consideration allocated to each deliverable, limited to the amount not contingent on future performance, is then recognized to revenue when the basic revenue recognition criteria are met for the respective deliverable. The Company determines VSOE based on historical standalone sales to customers. In determining VSOE, the Company requires that a substantial majority of the selling prices fall within a reasonably narrow pricing range. VSOE exists for all of the Company’s subscription plans. The Company uses BESP as the selling price for its product offerings as the Company is not able to determine VSOE of fair value from standalone sales or third-party evidence of selling price (TPE). The Company estimates BESP for a product by considering company-specific factors such as pricing objectives, direct product and other costs, bundling and discounting practices, and contractually stated prices. A portion of the Company’s software subscriptions and product revenues are generated through sales by resellers. When the Company assumes a majority of the business risks associated with performance of the contractual obligations, it records these revenues at the gross amount paid by the customer with amounts retained by the resellers recognized as sales and marketing expense. The Company’s assumption of such business risks is evidenced when, among other things, it takes responsibility for delivery of the product or subscription, is involved in establishing pricing of the arrangement, assumes credit and inventory risk, and is the primary obligor in the arrangement. When a reseller assumes the majority of the business risks associated with the performance of the contractual obligations, the Company records the associated revenue at the net amount received from the reseller. The Company recognizes revenue from resellers when the following criteria are met: • persuasive evidence of an arrangement exists through a contract with the customer; • the subscription is being provided to the customer or the product has been delivered; • the amount of fees to be paid by the customer is fixed or determinable; and • the collection of the fees is reasonably assured. The Company’s deliverables sold through its reseller agreements consist of the Company’s software subscriptions and products. Subscriptions sold through resellers are recognized on a straight-line basis over the period the subscriptions are provided to the end customer. Phones sold through resellers are shipped directly to the end customer and are recognized when title transfers to the end customer. Revenue from resellers has predominantly been recorded on a gross basis for all periods presented. The Company records reductions to revenue for estimated sales returns and customer credits at the time the related revenue is recognized. Sales returns and customer credits are estimated based on historical experience, current trends, and expectations regarding future experience. Customer billings related to taxes imposed by and remitted to governmental authorities on revenue-producing transactions are reported on a net basis. When such remitted taxes exceed the amount billed to customers, the cost is included in general and administrative expenses. Amounts billed in excess of revenue recognized for the period are reported as deferred revenue on the consolidated balance sheet. The Company’s deferred revenue consists primarily of unearned revenue on annual and monthly subscription plans. During the year ended December 31, 2014, the Company received one-time up-front payments for implementation services to be performed in connection with its carrier agreements with BT and TELUS. These amounts are being amortized on a straight-line basis over their respective initial contractual terms beginning in 2015. The BT and TELUS arrangements have initial contractual terms of three to five years, which approximates the estimated average customer life of each respective agreement. Accordingly, the portion of these one-time up-front payments that is expected to be earned after December 31, 2017, or $0.4 million, is included as a component of other long-term liabilities in the consolidated balance sheets. Cost of Revenues Cost of software subscriptions revenue primarily consists of costs of network capacity purchased from third-party telecommunications providers, network operations, costs to build out and maintain data centers, including co-location fees for the right to place the Company’s servers in data centers owned by third-parties, depreciation of the servers and equipment, along with related utilities and maintenance costs, personnel costs associated with customer care and support of the functionality of the Company’s platform and data center operations, including share-based compensation expenses, and allocated costs of facilities and information technology. Cost of software subscriptions revenue is expensed as incurred. Cost of other revenue is comprised primarily of the cost associated with purchased phones that fell outside of the agency model, shipping costs, costs of professional services, and allocated costs of facilities and information technology related to the procurement, management and shipment of phones. Cost of other revenue is expensed in the period product is delivered to the customer. Share-Based Compensation Share-based compensation expense resulting from options, restricted stock units (RSUs), and employee stock purchase plan (ESPP) rights granted is measured as the grant date fair value of the award and is recognized using the straight-line attribution method over the requisite service period of the award, which is generally the vesting period. The Company estimates the fair value of stock options and ESPP rights using the Black-Scholes-Merton option-pricing model. The Company estimates the fair value of RSUs as the closing market value of its Class A Common Stock on the grant date. Compensation expense for stock options and RSUs granted to non-employees is revalued, or marked to market, as of each reporting date until the stock options and RSUs are vested. Compensation expense is recognized net of estimated forfeiture activity, which is based on historical forfeiture rates. Research and Development Research and development expenses consist primarily of third-party contractor costs, personnel costs, technology license expenses, and depreciation associated with research and development equipment. Research and development costs are expensed as incurred. Advertising Costs Advertising costs, which include various forms of e-commerce such as search engine marketing, search engine optimization and online display advertising, as well as more traditional forms of media advertising such as radio and billboards, are expensed as incurred and were $41.6 million, $34.3 million, and $27.1 million for the years ended December 31, 2016, 2015 and 2014, respectively. Commissions Commissions consist of variable compensation earned by sales personnel and third-party resellers. Sales commissions associated with the acquisition of a new customer contract are recognized as sales and marketing expense at the time the customer has entered into a binding agreement. Income Taxes The Company accounts for income taxes using the asset and liability method. Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis. Deferred tax assets and liabilities are measured using enacted tax rates in effect for the year in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in operations in the period that includes the enactment date. The Company records a valuation allowance to reduce its deferred tax assets to the amount of future tax benefit that is more likely than not to be realized. As of December 31, 2016, except for deferred tax assets associated with its subsidiaries in the Netherlands and China, the Company recorded a full valuation allowance against all other net deferred tax assets due to its history of operating losses. The Company classifies interest and penalties on unrecognized tax benefits as income tax expense. Segment Information The Company has determined the chief executive officer is the chief operating decision maker. The Company’s chief executive officer reviews financial information presented on a consolidated basis for purposes of assessing performance and making decisions on how to allocate resources. Accordingly, the Company has determined that it operates in a single reportable segment. Indemnification Certain of the Company’s agreements with resellers and customers include provisions for indemnification against liabilities if its subscriptions infringe upon a third-party’s intellectual property rights. At least quarterly, the Company assesses the status of any significant matters and its potential financial statement exposure. If the potential loss from any claim or legal proceeding is considered probable and the amount or the range of loss can be estimated, the Company accrues a liability for the estimated loss. The Company has not incurred any material costs as a result of such indemnification provisions and the Company has not accrued any liabilities related to such obligations in the consolidated financial statements as of December 31, 2016 or 2015. Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2014-09, Revenue from Contracts with Customers (Topic 606), In addition, the standard requires disclosure of the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. The Company is currently evaluating the potential changes from adopting the new standard on its financial statements and disclosures. The Company is in the process of implementing appropriate changes to its business processes, systems and controls to support revenue recognition and disclosures under the new standard. Based on this evaluation, the Company will adopt the requirements of the new standard in the first quarter of 2018 and anticipates using the modified retrospective transition method. Additionally, as the Company continues to assess the new standard along with industry trends and internal progress, the Company may adjust its implementation plan accordingly. Under the new standard, the Company expects to capitalize certain sales commission costs and in some cases recognize revenue earlier for subscription plans with free periods and products sold at discounts. The impact of adopting the new standard on the Company’s total revenues is not expected to be material. However, the Company anticipates the most significant impacts of adopting the new standard primarily relates to the deferral of sales commissions, which previously were expensed as incurred and to the incremental disclosure requirements. Under the new standard, certain commissions will be capitalized and amortized over the expected period of benefit. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) In March 2016, the FASB issued ASU 2016-09, Compensation-Stock Compensation: Improvements to Employee Share-Based Payment Accounting (Topic 718) In August 2016, the FASB issued ASU 2016-15, Classification of Certain Cash Receipts and Cash Payments In October 2016, the FASB issued ASU 2016-16, Intra-Entity Transfers of Assets Other Than Inventory In November 2016, the FASB issued ASU 2016-18, Restricted Cash Reclassification Certain immaterial items previously reported have been reclassified to conform to the current year’s reporting presentation.

Agency Agreement with Westcon G

Agency Agreement with Westcon Group	12 Months Ended
	Dec. 31, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Agency Agreement with Westcon Group	Note 2. Agency Agreement with Westcon Group In January 2016, the Company entered into a sales agency agreement with Westcon Group, Inc. (Westcon), a global distributor of communications devices, to provide the phones purchased by customers. Under this agreement, the Company is an agent of Westcon and receives a commission for its services, which primarily include referring phone sales to Westcon. Westcon will provide phones directly to the Company’s customers instead of the Company purchasing phones from third-party vendors and reselling the phones to the Company’s customers. Commission revenues from the arrangement are recorded as the Company is the agent for these sales based on the following criteria: • the Company is not the primary obligor in the arrangement and the customer contracts for the sales of phones are entered into with Westcon; • the Company does not have latitude to establish pricing with customers as the sales agency agreement restricts the prices at which phones may be sold by the Company; • the Company does not have collection risk for phones sold under this model since it is entitled to a sales commission regardless of whether the customer pays Westcon; • the Company does not carry inventory and does not have general inventory risk; and • warranty responsibility and services are provided by Westcon. During the three months ended June 30, 2016, the Company completed its transition of direct phone sales to Westcon, which excluded carriers’ phone sales. The Company did not transition the carrier partners to the agency model as the billing relationships to these customers are through the carriers. The Company’s sales of phones that are provided free or significantly discounted to customers are not part of the sales agency agreement with Westcon. The Company recognizes revenues and costs from these sales as the Company is the primary obligor and has latitude in determining pricing. In December 2016, the Company terminated the sales agency agreement and entered into a reseller (direct sale) agreement with Westcon. Effective January 1, 2017, the Company will switch from the agency agreement to the reseller agreement whereby the Company will no longer serve as an agent for referring phone sales to Westcon and will no longer receive commissions for its services. Under the reseller agreement, the Company will purchase phones directly from Westcon for resale to customers. Revenues and costs for sales under the reseller agreement will be recognized as the Company is the primary obligor for order fulfillment, has latitude in determining pricing, and will assume general inventory risk.

Change in Presentation

Change in Presentation	12 Months Ended
	Dec. 31, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Change in Presentation	Note 3. Change in Presentation As a result of the new sales agency model, the Company replaced the product revenues line in its consolidated statements of operations with a line called other revenues, which includes the commission revenues earned as an agent of Westcon, product revenues from sales of phones not sold under the sales agency agreement with Westcon, phone sales to carrier partners, phone rentals, and professional implementation services. Correspondingly, the Company replaced the costs of product revenues line in its consolidated statements of operations with a line called costs of other revenues, which includes the costs for the above items. For the years ended December 31, 2016, 2015 and 2014, the majority of other revenues consisted of product revenues from sales of phones that fell outside the sales agency agreement with Westcon. Accordingly, to provide a comparison of product revenues and product cost of revenues prior to and subsequent to the change in presentation, product revenues were $13.3 million, $23.3 million, and $19.2 million for the years ended December 31, 2016, 2015 and 2014, respectively. Product cost of revenues were $15.8 million, $20.3 million, and $17.9 million for the years ended December 31, 2016, 2015, and 2014, respectively.

Financial Statement Components

Financial Statement Components	12 Months Ended
	Dec. 31, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Financial Statement Components	Note 4. Financial Statement Components Cash and cash equivalents consisted of the following (in thousands): December 31, December 31, 2016 2015 Cash $ 40,908 $ 18,522 Money market funds 119,447 119,066 Total cash and cash equivalents $ 160,355 $ 137,588 Accounts receivable, net consisted of the following (in thousands): December 31, December 31, 2016 2015 Accounts receivable $ 26,731 $ 15,509 Unbilled accounts receivable 3,946 4,031 Allowance for doubtful accounts (434 ) (377 ) Accounts receivable, net $ 30,243 $ 19,163 Property and equipment, net consisted of the following (in thousands): December 31, December 31, 2016 2015 Computer hardware and software $ 61,546 $ 49,774 Internal-use software development costs 9,931 7,432 Furniture and fixtures 4,508 3,610 Leasehold improvements 2,596 2,412 Property and equipment, gross 78,581 63,228 Less: accumulated depreciation and amortization (46,587 ) (35,068 ) Property and equipment, net $ 31,994 $ 28,160 Total depreciation and amortization expense related to property and equipment was $13.6 million, $12.9 million, and $10.4 million for the fiscal years ended December 31, 2016, 2015 and 2014, respectively. Accrued liabilities consisted of the following (in thousands): December 31, December 31, 2016 2015 Accrued compensation and benefits $ 14,041 $ 10,128 Accrued sales, use, and telecom related taxes 7,220 5,243 Accrued marketing 5,082 3,930 Other accrued expenses 21,979 15,401 Total accrued liabilities $ 48,322 $ 34,702

Fair Value of Financial Instrum

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Note 5. Fair Value of Financial Instruments Fair value is based on the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The Company measures and reports certain cash equivalents, including money market funds and certificates of deposit, at fair value in accordance with the provisions of the authoritative accounting guidance that addresses fair value measurements. This guidance establishes a hierarchy for inputs used in measuring fair value that maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that the most observable inputs be used when available. The hierarchy is broken down into three levels based on the reliability of the inputs as follows: Level 1: Valuations based on observable inputs that reflect unadjusted quoted prices in active markets for identical assets or liabilities. Level 2: Valuations based on observable inputs other than Level 1 inputs, such as quoted prices for similar assets or liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the asset or liability. Level 3: Valuations based on unobservable inputs that are supported by little or no market activity and that are based on management’s assumptions, including fair value measurements determined by using pricing models, discounted cash flow methodologies or similar techniques. The financial assets carried at fair value were determined using the following inputs (in thousands): Balance at December 31, (Level 1) (Level 2) (Level 3) Cash equivalents: Money market funds $ 119,447 $ 119,447 $ — $ — Other assets: Certificates of deposit $ 530 $ — $ 530 $ — Balance at December 31, (Level 1) (Level 2) (Level 3) Cash equivalents: Money market funds $ 119,066 $ 119,066 $ — $ — Other assets: Certificates of deposit $ 530 $ — $ 530 $ — The At December 31, 2016 and 2015, the Company estimated the fair value of its debt using an expected present value technique, which is based on observable market inputs using interest rates currently available to companies of similar credit standing for similar terms and remaining maturities, and considering its own credit risk. The estimated fair value of the Company’s current and non-current debt obligations was $14.9 million at December 31, 2016, compared to its carrying amount of $14.8 million at that date. The estimated fair value of the Company’s current and non-current debt obligations was $19.0 million at December 31, 2015, compared to its carrying amount of $18.6 million at that date. If the debt was measured at fair value in th e consolidated balance sheets, the Company’s current and non-current debt would be classified in Level 2 of the fair value hierarchy.

Business Combinations

Business Combinations	12 Months Ended
	Dec. 31, 2016
Business Combinations [Abstract]
Business Combinations	Note 6. Business Combinations In June 2015, the Company acquired Glip, Inc. (Glip), a cloud messaging and collaboration company based in Boca Raton, Florida. Glip is a provider of team messaging services, integrated with project management, group calendars, notes, annotations, and file sharing. The objective of the acquisition was to extend the Company’s platform by adding team messaging and collaboration services such as calendar, project management, and document sharing. The consideration for the acquisition, net of cash acquired, which also included the fair value of contingent consideration payable upon achievement of certain earn out milestones and the fair value of common stock issuable to the sellers, was $11.9 million. Of the consideration, $1.5 million of cash was held back by the Company upon closing as security for certain indemnification obligations of such stockholders. In June 2016, the Company paid the $1.5 million in full. The consideration exchanged consisted of the following (in thousands): Cash, net of cash acquired $ 4,670 Common stock issued (223,190 shares) 3,447 Holdback based on standard representations and warranties 1,500 Total initial consideration 9,617 Milestone based earn out 2,289 Total consideration $ 11,906 The $3.4 million fair value of the 223,190 unregistered common shares issued as part of the consideration paid for Glip ($3.8 million before a $0.4 million discount due to a 6-month restriction of resale as a result of SEC Rule 144 for issuance of unregistered shares) was determined on the basis of the five day weighted average closing market price of the Company’s common shares preceding the acquisition date. The initial fair value of the milestone based earn out liability was determined to be $2.3 million using various estimates, including probabilities of success and discount rates. During the year ended December 31, 2016, the Company issued 45,893 shares of the Company’s Class A common stock to settle certain milestones achieved. Additionally, under the terms of the acquisition, the Company may also pay up to $2.0 million in payments at the end of a two-year period to certain Glip employees, who continue to be employees of the Company, which are accounted for as a post-combination expense. At December 31, 2016, the contingent payment liability is $1.4 million and is classified as a current liability in the consolidated balance sheets as settlement will occur in 2017. At December 31, 2015, the contingent payment liability is $0.6 million and is classified as a non-current liability in the consolidated balance sheets. The following table summarizes the fair value of assets acquired as of the date of acquisition (in thousands): Cash and cash equivalents $ 74 Acquired intangible assets 3,850 Goodwill 7,982 Net assets acquired $ 11,906 The Company has included the financial results of Glip, which were not material, in the consolidated statements of operations from the date of acquisition. The goodwill balance is primarily attributed to the assembled workforce and expanded market opportunities when integrating Glip’s cloud messaging and collaboration technology with the Company’s other offerings. The goodwill balance is not deductible for U.S. income tax purposes. The following table sets forth the fair value components of identifiable acquired intangible assets (in thousands) and their estimated useful lives (in years) as of the date of acquisition: Fair Value Estimated Useful Life Customer relationships $ 840 2 years Developed technology 3,010 5 years Total identifiable acquired intangible assets subject to amortization $ 3,850 The amount recorded for developed technology represents the estimated fair value of Glip’s cloud messaging and collaboration technology. The amount recorded for customer relationships represents the fair value of the underlying relationships with Glip customers. The carrying values of intangible assets at December 31, 2016 and 2015 are as follows (in thousands): December 31, 2016 December 31, 2015 Estimated Lives Cost Accumulated Amortization Acquired Intangibles, Net Accumulated Amortization Acquired Intangibles, Net Customer relationships 2 years $ 840 $ 660 $ 180 $ 240 $ 600 Developed technology 5 years 3,010 946 2,064 344 2,666 Total acquired intangible assets $ 3,850 $ 1,606 $ 2,244 $ 584 $ 3,266 Amortization expense from acquired intangible assets for the years ended December 31, 2016 and 2015 was $1.1 million and $0.6 million, respectively. Amortization of developed technology is included in research and development expenses and amortization of customer relationships is included in sales and marketing expenses in the consolidated statements of operations. As of December 31, 2016, the weighted-average amortization periods for customer relationships and developed technology are approximately 0.4 years and 3.4 years, respectively. Estimated amortization expense for acquired intangible assets for the following five fiscal years and thereafter is as follows (in thousands): 2017 $ 782 2018 602 2019 602 2020 258 2021 — Total estimated amortization expense $ 2,244

Debt

Debt	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Debt	Note 7. Debt As of December 31, 2016, the Company’s debt was comprised of borrowings under the Third Amended and Restated Loan and Security Agreement dated March 30, 2015 (SVB Agreement), as amended, with Silicon Valley Bank (SVB). The 2013 Term Loan was borrowed on December 31, 2013 with a principal amount of $15.0 million, which is being repaid in 48 equal monthly installments of principal, plus accrued and unpaid interest. Interest is due monthly and accrues at a floating rate based on the Company’s option of an annual rate of either the (i) prime rate plus a margin of 0.75% or 1.00% or (ii) adjusted LIBOR rate (based on one, two, three or six-month interest periods) plus a margin of 3.75% or 4.00%, in each case such margin being determined based on cash balances maintained with SVB. The Company elected the prime rate option. In May 2016, the terms of the SVB Agreement were amended to reduce the margin on the annual rate of the 2013 Term Loan to either (i) prime rate plus a margin of 0.25% or 0.50% or (ii) adjusted LIBOR rate (based on one, two, three, or six-month interest periods) plus a margin of 3.25% or 3.50%, resulting in a current interest rate of 4.00% based on the prime rate option and cash balance maintained with SVB. is payable subsequent to December 31, 2017 and is classified as a non-current liability in the accompanying consolidated balance sheet. The revolving line of credit provides for a maximum borrowing of up to $15.0 million in principal amount, subject to limits based on recurring software subscription revenue amounts as defined in the SVB Agreement. The recurring software subscription revenue requirement is not expected to limit the amount of borrowings available under the line of credit. Under the line of credit, interest is paid monthly and accrues at a floating rate based on the Company’s option of an annual rate of either the (i) prime rate plus a margin of 0.25% or 0.50% or (ii) adjusted LIBOR rate (based on one, two, three or six-month interest periods) plus a margin of 3.25% or 3.50%, in each case such margin being determined based on cash balances maintained with SVB. The Company elected the prime rate option. In August 2015, the terms of the SVB Agreement were amended to extend the maturity of the revolving line of credit from August 13, 2015 to August 14, 2017. In May 2016, the terms of the SVB Agreement were amended to reduce the margin on the annual rate of the revolving line of credit to either the (i) prime rate plus a margin of 0% or 0.25% or (ii) adjusted LIBOR rate (based on one, two, three, or six-month interest periods) plus a margin of 3.0% to 3.25%, resulting in a current interest rate of 3.75% based on the prime rate option and cash balance maintained with SVB. As of December 31, 2016, the outstanding principal balance and the available borrowing capacity of the line of credit were $10.8 million and $4.2 million, respectively. The outstanding principal balance is classified as a current liability in the consolidated balance sheet as the principal balance is due in August 2017. The Company has pledged all of its assets, excluding intellectual property, as collateral to secure its obligations under the SVB agreement. The SVB agreement contains customary negative covenants that limit the Company’s ability to, among other things, incur additional indebtedness, grant liens, make investments, repurchase stock, pay dividends, transfer assets and merge or consolidate. The SVB agreement also contains customary affirmative covenants, including requirements to, among other things, (i) maintain minimum cash balances representing the greater of $10.0 million or three times the Company’s quarterly cash burn rate, as defined in the agreement, and (ii) maintain minimum EBITDA levels, as determined in accordance with the agreement. On March 30, 2016, the Company adjusted certain financial covenant thresholds to expand its ability to invest in certain foreign subsidiaries and property and equipment. The Company was in compliance with all covenants under its credit agreement with SVB as of December 31, 2016. As of December 31, 2016, future debt principal payments are scheduled as follows (in thousands): 2017 $ 14,528 2018 312 Total future repayments of debt $ 14,840

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2016
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 8. Commitments and Contingencies Leases The Company leases facilities for office space under non-cancelable operating leases for its U.S. and international locations and has entered into capital lease arrangements to obtain property and equipment for its operations. In addition, the Company leases space from third-party datacenter hosting facilities under co-location agreements to support its cloud infrastructure. As of December 31, 2016, non-cancelable leases expire on various dates between 2017 and 2021 and require the following future minimum lease payments by year (in thousands): Capital Leases Operating Leases Year ending December 31, 2017 $ 185 $ 7,281 2018 — 7,164 2019 — 5,945 2020 — 3,451 2021 — 2,131 Total future minimum lease payments $ 185 $ 25,972 Less: amount representing interest (4 ) Total capital lease obligation $ 181 Property and equipment recorded under capital leases consisted of the following (in thousands): December 31, 2016 2015 Property and equipment acquired under capital lease $ 3,149 $ 3,149 Less: accumulated amortization (2,600 ) (2,212 ) Property and equipment acquired under capital lease, net $ 549 $ 937 Operating leases for certain office facilities include scheduled periods of abatement and escalation of rental payments. The Company recognizes rent expense on a straight-line basis for all operating lease arrangements with the difference between required lease payments and rent expense recorded as deferred rent. Total rent expense was $4.5 million, $4.0 million, and $2.2 million for the fiscal years ended December 31, 2016, 2015 and 2014, respectively. Sales Tax Liability The Company regularly increases its sales and marketing activities in various states within the U.S., which may create nexus in those states to collect sales taxes on sales to customers. Although the Company is diligent in collecting and remitting such taxes, there is uncertainty as to what constitutes sufficient in state presence for a state to levy taxes, fees, and surcharges for sales made over the Internet. As of December 31, 2016 and 2015, the Company recorded a long-term sales tax liability of $3.1 million and $3.7 million, respectively, based on its best estimate of the probable liability for the loss contingency incurred as of those dates. The Company’s estimate of a probable outcome under the loss contingency is based on analysis of its sales and marketing activities, revenues subject to sales tax, and applicable regulations in each state in each period. No significant adjustments to the long-term sales tax liability have been recognized in the accompanying consolidated financial statements for changes to the assumptions underlying the estimate. However, changes in management’s assumptions may occur in the future as the Company obtains new information which can result in adjustments to the recorded liability. Increases and decreases to the long-term sales tax liability are recorded as general and administrative expense. The Company recorded a current sales tax liability for non-contingent amounts expected to be remitted in the next twelve months of $6.0 million and $4.4 million as of December 31, 2016 and 2015, respectively, which is included in accrued liabilities in the consolidated balance sheet. Legal Matters The Company determines whether an estimated loss from a contingency should be accrued by assessing whether a loss is deemed probable and can be reasonably estimated. The Company assesses its potential liability by analyzing specific litigation and regulatory matters using reasonably available information. The Company develops its views on estimated losses in consultation with inside and outside counsel, which involves a subjective analysis of potential results and outcomes, assuming various combinations of appropriate litigation and settlement strategies. Legal fees are expensed in the period in which they are incurred. TCPA Matter On April 21, 2016, Supply Pro Sorbents, LLC (SPS) filed a putative class action against the Company in the United States District Court for the Northern District of California (Court), alleging common law conversion and violations of the federal Telephone Consumer Protection Act (TCPA) arising from fax cover sheets used by the Company’s customers when sending facsimile transmissions over the Company’s system (Lawsuit). SPS seeks statutory damages, costs, attorneys’ fees and an injunction in connection with its TCPA claim, and unspecified damages and punitive damages in connection with its conversion claim. On July 6, 2016, the Company filed a Petition for Expedited Declaratory Ruling before the Federal Communications Commission (FCC), requesting that the FCC issue a ruling clarifying certain portions of its regulations promulgated under TCPA at issue in the Lawsuit (Petition). The Petition remains pending. On July 8, 2016, the Company filed a motion to dismiss the Lawsuit in its entirety, along with a collateral motion to dismiss or stay the Lawsuit pending a ruling by the FCC on the Company’s Petition. On October 7, 2016, the Court granted the Company’s motion to dismiss and gave SPS 20 days to amend its complaint. The Court concurrently dismissed the Company’s motion to dismiss or stay as moot. SPS filed its amended complaint on October 27, 2016, alleging the same theories and claims. On November 21, 2016, the Company filed a motion to dismiss the amended complaint, along with a renewed motion to dismiss or stay the case pending resolution of the FCC Petition. The motions to dismiss and to stay the Lawsuit are fully briefed and under submission to the Court. Discovery has not yet commenced. The Company intends to vigorously defend itself in the Lawsuit. Litigation is inherently uncertain, however, and it is too early in this proceeding to predict the outcome of this Lawsuit. Based on the information known by the Company as of the date of this filing and the rules and regulations applicable to the preparation of the Company’s consolidated financial statements, it is not possible to provide an estimated amount of any such loss or range of loss that may occur. As of December 31, 2015, there were no significant ongoing legal matters and the Company did not have any accrued liabilities recorded for such loss contingencies. Employee Agreements The Company has signed various employment agreements with executives and key employees pursuant to which if the Company terminates their employment without cause or if the employee terminates his or her employment for good reason following a change of control of the Company, the employees are entitled to receive certain benefits, including severance payments, accelerated vesting of stock options and RSUs and continued COBRA coverage. As of December 31, 2016, no triggering events which would cause these provisions to become effective have occurred. Therefore, no liabilities have been recorded for these agreements in the consolidated financial statements.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Stockholders' Equity	Note 9. Stockholders’ Equity In connection with the Company’s initial public offering (IPO), the Company reincorporated in Delaware on September 26, 2013. The Delaware certificate of incorporation provides for two classes of common stock: Class A and Class B common stock, both with a par value of $0.0001 per share. In addition, the certificate of incorporation authorizes shares of undesignated preferred stock with a par value of $0.0001 per share. The terms of preferred stock are described below. Preferred Stock The board of directors may, without further action by the stockholders, fix the rights, preferences, privileges and restrictions of up to an aggregate of 100,000,000 shares of preferred stock in one or more series and authorizes their issuance. These rights, preferences, and privileges could include dividend rights, conversion rights, voting rights, terms of redemption, liquidation preferences, sinking fund terms and the number of shares constituting any series or the designation of such series, any or all of which may be greater than the rights of the Class A and Class B common stock. As of December 31, 2016 and 2015, there were 100,000,000 shares of preferred stock authorized and no shares issued or outstanding. Class A and Class B Common Stock The Company has authorized 1,000,000,000 and 250,000,000 shares of Class A common stock and Class B common stock for issuance. Holders of Class A common stock and Class B common stock have identical rights for matters submitted to a vote of the Company’s stockholders. Holders of Class A common stock are entitled to one vote per share of Class A common stock and holders of Class B common stock are entitled to 10 votes per share of Class B common stock. Holders of shares of Class A common stock and Class B common stock vote together as a single class on all matters (including the election of directors) except for specific circumstances that would adversely affect the powers, preferences, or rights of a particular class of common stock. Subject to preferences that may apply to any shares of preferred stock outstanding at the time, holders of Class A and Class B common stock share equally, identically and ratably, on a per share basis, with respect to any dividend or distribution of cash, property or shares of the Company’s capital stock. Holders of Class A and Class B common stock also share equally, identically, and ratably in all assets remaining after the payment of any liabilities and liquidation preferences and any accrued or declared but unpaid dividends, if any, with respect to any outstanding preferred stock at the time. Each share of Class B common stock is convertible at any time at the option of the holder into one share of Class A common stock. In addition, each share of Class B common stock will convert automatically to Class A common stock upon: (i) the date specified by an affirmative vote or written consent of holders of at least 67% of the outstanding shares of Class B common stock, or (ii) the seven year anniversary of the closing date of the IPO (October 2, 2020). Shares of Class A common stock reserved for future issuance were as follows (in thousands): December 31, 2016 Preferred stock 100,000 Class B common stock 13,091 2013 Employee stock purchase plan 2,292 2013 Equity incentive plan: Outstanding options and restricted stock unit awards 10,938 Available for future grants 8,703 135,024 As of December 31, 2016 and 2015, there were 0 and 2,330 shares of common stock outstanding related to the early exercise of non-vested options subject to repurchase at the original exercise price by the Company upon termination of service by an employee.

Share-Based Compensation

Share-Based Compensation	12 Months Ended
	Dec. 31, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Share-Based Compensation	Note 10. Share-Based Compensation A summary of share-based compensation expense recognized in the Company’s consolidated statements of operations is as follows (in thousands): Year Ended December, 31 2016 2015 2014 Cost of revenues $ 3,165 $ 2,054 $ 1,294 Research and development 7,296 5,387 3,343 Sales and marketing 10,902 7,200 5,260 General and administrative 9,477 7,447 5,619 Total share-based compensation expense $ 30,840 $ 22,088 $ 15,516 A summary of share-based compensation expense by award type is as follows (in thousands): Year Ended December, 31 2016 2015 2014 Options $ 9,626 $ 11,170 $ 10,323 Employee stock purchase plan rights 1,737 1,365 1,628 Restricted stock units 19,477 9,553 3,565 Total share-based compensation expense $ 30,840 $ 22,088 $ 15,516 Equity Incentive Plans In September 2013, the Board adopted and the Company’s stockholders approved the 2013 Equity Incentive Plan (2013 Plan), which became effective on September 26, 2013. In connection with the adoption of the 2013 Plan, the Company terminated the 2010 Equity Incentive Plan (2010 Plan), under which stock options had been granted prior to September 26, 2013. The 2010 Plan was established in September 2010, when the 2003 Equity Incentive Plan (2003 Plan) was terminated. After the termination of the 2003 and 2010 Plans, no additional options were granted under these plans; however, options previously granted under these plans will continue to be governed by these plans, and will be exercisable into shares of Class B common stock. In addition, options authorized to be granted under the 2003 and 2010 Plans, including forfeitures of previously granted awards are authorized for grant under the 2013 Plan. A total of 6,200,000 shares of Class A common stock have been reserved for issuance under the 2013 Plan. The 2013 Plan includes an annual increase on the first day of each fiscal year beginning in 2014, equal to the least of: (i) 6,200,000 shares of Class A common stock; (ii) 5% of the outstanding shares of all classes of common stock as of the last day of the Company’s immediately preceding fiscal year; or (iii) such other amount as the board of directors may determine. During the year ended December 31, 2016, a total of 3,598,122 shares of Class A common stock were added to the 2013 Plan in connection with the annual automatic increase provision. As of December 31, 2016, a total of 8,702,558 shares remain available for grant under the 2013 Plan. The plans permit the grant of stock options and other share-based awards, such as restricted stock units, to employees, officers, directors, and consultants by the board of directors. Option awards are generally granted with an exercise price equal to the fair market value of the Company’s Class A common stock at the date of grant. Option awards generally vest according to a graded vesting schedule based on four years of continuous service. On January 29, 2014, the board of directors approved an amendment to decrease the contractual term of all equity awards issued from the 2013 Plan from 10 years to 7 years for all awards granted after January 29, 2014. A summary of option activity under all of the plans at December 31, 2016 and changes during the periods then ended is presented in the following table: Weighted- Number of Weighted- Average Aggregate Options Average Contractual Intrinsic Outstanding Exercise Price Term Value (in thousands) Per Share (in Years) (in thousands) Outstanding at December 31, 2013 11,156 $ 5.87 7.7 $ 139,484 Granted 1,302 15.12 Exercised (2,673 ) 1.97 Canceled/Forfeited (627 ) 7.19 Outstanding at December 31, 2014 9,158 $ 8.23 7.2 $ 61,367 Granted 1,881 16.35 Exercised (2,323 ) 6.82 Canceled/Forfeited (668 ) 11.42 Outstanding at December 31, 2015 8,048 $ 10.27 6.2 $ 107,091 Granted 547 16.53 Exercised (962 ) 10.01 Canceled/Forfeited (249 ) 15.50 Outstanding at December 31, 2016 7,384 $ 10.59 5.3 $ 74,065 Vested and expected to vest as of December 31, 2016 7,083 $ 10.36 5.3 $ 72,684 Exercisable as of December 31, 2016 5,359 $ 8.68 5.1 $ 63,893 The total intrinsic values of options exercised during the years ended December31, 2016, 2015, and 2014 were as follows (in thousands): Year Ended December 31, 2016 2015 2014 Total intrinsic value of options exercised $ 10,718 $ 28,336 $ 41,454 Valuation Assumptions The Company estimated the fair values of each option awarded on the date of grant using the Black-Scholes-Merton option-pricing model, which requires inputs including the fair value of common stock, expected term, expected volatility, risk-free interest rate, and dividend yield. Fair Value of Common Stock The Company uses the daily adjusted closing stock price of its Class A common stock as reported by the New York Stock Exchange. Expected Term The expected term represents the period that option awards are expected to be outstanding. Prior to the fourth quarter of 2014, the Company did not have sufficient historical information to develop reasonable expectations about future exercise behavior. Therefore, the expected term for options issued to employees was calculated as the mean of the option vesting period and the contractual term (the Simplified Method) as these options were determined to be “plain-vanilla” as defined under current guidance. Beginning with the fourth quarter of 2014, the Company began incorporating its own historical data, assigning a 25% weighting to the Company’s historical data and a 75% weighting to the Simplified Method estimate. As time progressed and the Company generated additional historical data, the weighting of the Company’s historical data has increased while the weighting of the Simplified Method data has decreased. Accordingly, in the fourth quarters of 2015 and 2016, the Company’s historical data was weighted as 50% and 75%, respectively, while the Simplified Method data was weighted as 50% and 25%, respectively. The expected term for options issued to non-employees is the remaining contractual term. Expected Volatility The expected stock price volatility of common stock was derived from the historical volatilities of a peer group of similar publicly traded companies over a period that approximates the expected term of the option. Beginning in the fourth quarter of 2014, the Company incorporated its own historical volatility assigning a 25% weighting to the Company’s historical data and a 75% weighting to the historical volatilities of the peer group of similarly publicly traded companies. As time progressed and the Company generated additional historical data, the weighting of the Company’s historical data has increased while the weighting of the peer group data has decreased. Accordingly, in the fourth quarters of 2015 and 2016, the Company’s historical volatility was weighted as 50% and 75%, respectively, while the peer group data was weighted as 50% and 25%, respectively. Risk-Free Interest Rate The risk-free interest rate was based on the yield available on U.S. Treasury zero-coupon issues with a term that approximates the expected term of the option. Expected Dividend Yield The expected dividend yield was 0% as the Company has not declared, nor paid, and does not expect to pay cash dividends. The weighted-average assumptions used in the option-pricing model and the resulting grant date fair value of stock options granted in the periods presented were as follows: Year ended December 31, 2016 2015 2014 Expected term for employees (in years) 4.7 4.8 4.6 Expected term for non-employees (in years) 5.9 7.1 7.0 Expected volatility 47 % 48 % 48 % Risk-free interest rate 1.12 % 1.22 % 1.41 % Expected dividend yield 0 % 0 % 0 % Grant date fair value of employee options $ 6.72 $ 6.78 $ 6.16 As of December 31, 2016 and 2015, there was approximately $11.0 million and $19.6 million of unrecognized share-based compensation expense, net of estimated forfeitures, related to stock option grants, which will be recognized on a straight-line basis over the remaining weighted-average vesting periods of approximately 2.0 years and 2.5 years, respectively. Employee Stock Purchase Plan The Employee Stock Purchase Plan (ESPP) allows eligible employees to purchase shares of the Company’s Class A common stock at a discounted price, through payroll deductions of up to the lesser of 15% of their eligible compensation or the IRS allowable limit per calendar year. A participant may purchase a maximum of 3,000 shares during an offering period. The offering periods are for a period of six months and generally start on the first trading day on or after May 11th and November 11th of each year. At the end of the offering period, the purchase price is set at the lower of: (i) 90% of the fair value of the Company’s common stock at the beginning of the six month offering period and (ii) 90% of the fair value of the Company’s Class A common stock at the end of the six month offering period. The ESPP provides for annual increases in the number of shares available for issuance under the ESPP on the first day of each fiscal year beginning in fiscal 2014, equal to the least of: (i) 1% of the outstanding shares of all classes of common stock on the last day of the immediately preceding year; (ii) 1,250,000 shares; or (iii) such other amount as may be determined by the board of directors. During the year ended December 31, 2016, a total of 719,624 shares of Class A common stock were added to the ESPP Plan in connection with the annual increase provision. At December 31, 2016, a total of 2,291,580 shares were available for issuance under the ESPP. The weighted-average assumptions used to value ESPP rights under the Black-Scholes-Merton option-pricing model and the resulting offering grant date fair value of ESPP rights granted in the periods presented were as follows: Year ended December 31, 2016 2015 2014 Expected term (in years) 0.5 0.5 0.5 Expected volatility 41 % 42 % 50 % Risk-free interest rate 0.50 % 0.25 % 0.07 % Expected dividend yield 0 % 0 % 0 % Offering grant date fair value of ESPP rights $ 5.29 $ 5.05 $ 3.93 As of December 31, 2016 and 2015, there was approximately $0.7 million and $1.1 million of unrecognized share-based compensation expense related to outstanding ESPP rights, which will be recognized on a straight-line basis over the remaining weighted average vesting periods of approximately 0.4 years and 0.4 years, respectively. Restricted Stock Units The 2013 Plan provides for the issuance of RSUs to employees and consultants. RSUs issued under the 2013 Plan generally vest over four years. A summary of activity of RSUs under the 2013 Plan at December 31, 2016 and changes during the periods then ended is presented in the following table: Number of Weighted- Aggregate RSUs Average Intrinsic Outstanding Grant Date Fair Value (in thousands) Value Per Share (in thousands) Outstanding at December 31, 2013 68 $ 17.22 $ 1,251 Granted 1,915 15.08 Released (110 ) 16.82 Canceled/Forfeited (134 ) 17.43 Outstanding at December 31, 2014 1,739 $ 14.87 $ 25,617 Granted 1,365 18.09 Released (571 ) 15.45 Canceled/Forfeited (245 ) 15.10 Outstanding at December 31, 2015 2,288 $ 16.63 $ 53,972 Granted 2,798 18.65 Released (1,096 ) 16.77 Canceled/Forfeited (436 ) 17.92 Outstanding at December 31, 2016 3,554 $ 18.01 $ 73,261 As of December 31, 2016 and 2015, there was a total of $46.9 million and $35.2 million of unrecognized share-based compensation expense, net of estimated forfeitures, related to RSUs, which will be recognized on a straight-line basis over the remaining weighted-average vesting periods of approximately 2.8 years and 3.0 years, respectively.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income Taxes	Note 11. Income Taxes The provision (benefit) for income taxes consisted of the following (in thousands): Year ended December 31, 2016 2015 2014 Current Federal $ — $ — $ — State 63 71 18 Foreign 209 85 114 Total current 272 156 132 Deferred Federal $ — $ (1,312 ) $ — State — (99 ) — Foreign (36 ) (8 ) (35 ) Total deferred (36 ) (1,419 ) (35 ) Total income tax provision (benefit) $ 236 $ (1,263 ) $ 97 Net loss before provision (benefit) for income taxes consisted of the following (in thousands): Year ended December 31, 2016 2015 2014 United States $ (27,908 ) $ (28,870 ) $ (50,065 ) International (1,165 ) (4,492 ) 1,822 Total net loss before benefit for income taxes $ (29,073 ) $ (33,362 ) $ (48,243 ) The provision (benefit) for income tax differed from the amounts computed by applying the U.S. federal income tax rate of 34% to pretax loss as a result of the following (in thousands): Year ended December 31, 2016 2015 2014 Federal tax benefit at statutory rate $ (9,885 ) $ (11,343 ) $ (16,403 ) State tax, net of federal provision (benefit) 28 (34 ) 12 Research and development credits (745 ) (667 ) (654 ) Share-based compensation 960 1,086 1,836 Other permanent differences 600 325 211 Foreign tax rate differential (225 ) (80 ) (33 ) Net operating losses not recognized 9,503 10,762 15,128 Release of valuation allowance associated with acquisitions — (1,312 ) — Total income tax provision (benefit) $ 236 $ (1,263 ) $ 97 The benefit for income taxes for 2015 relates primarily to the release of a valuation allowance of $1.4 million associated with nondeductible intangible assets recorded as part of the Glip acquisition, partially offset by state minimum income tax and income tax on our earnings in foreign jurisdictions. In connection with the acquisition of Glip, a deferred tax liability was established for the book-to-tax basis differences related to the non-goodwill intangible assets. The net deferred tax liability from this acquisition created an additional source of income to realize deferred tax assets. As the Company continues to maintain a full valuation allowance against its deferred tax assets, this additional source of income resulted in the release of the Company’s previously recorded valuation allowance against deferred assets. Consistent with the applicable guidance, the release of the valuation allowance resulting from the acquisition was recorded in the consolidated financial statements outside of acquisition accounting (i.e., recorded as a tax benefit to the consolidated statements of operations). In general, it is our practice and intention to reinvest the earnings of our non-U.S. subsidiaries in those operations. Undistributed earnings of foreign subsidiaries are immaterial for all periods presented. The types of temporary differences that give rise to significant portions of the Company’s deferred tax assets and liabilities are as follows (in thousands): Year ended December 31, 2016 2015 2014 Deferred tax assets Net operating loss and credit carry-forwards $ 59,863 $ 54,858 $ 45,552 Research and development credits 6,094 4,712 3,497 Sales tax liability 1,131 1,337 1,442 Share-based compensation 7,281 6,694 5,560 Accrued liabilities 6,525 6,090 4,676 Gross deferred tax assets 80,894 73,691 60,727 Valuation allowance (79,319 ) (71,514 ) (60,405 ) Total deferred tax assets 1,575 2,177 322 Deferred tax liabilities - Acquired intangibles (803 ) (1,164 ) — Deferred tax liabilities - Property and equipment (606 ) (883 ) (197 ) Net deferred tax assets $ 166 $ 130 $ 125 As a result of certain realization requirements of ASC 718, the table of deferred tax assets and liabilities does not include certain deferred tax assets as of December 31, 2016, 2015, and 2014, that arose directly from (or the use of which was postponed by) tax deductions related to equity compensation that are greater than the compensation recognized for financial reporting. Equity will be increased by $18.0 million if and when such deferred tax assets are ultimately realized. At December 31, 2016, the Company had net operating loss carry-forwards for federal and state income tax purposes of approximately $197.6 million and $137.6 million, respectively, available to reduce future income subject to income taxes. The federal net operating loss carry-forward will begin to expire in 2023 while the state net operating loss carry-forwards began to expire in 2013. The Company also has research credit carry-forwards for federal and California tax purposes of approximately $4.7 million and $5.2 million, respectively, available to reduce future income subject to income taxes. The federal research credit carry-forwards will begin to expire in 2028 and the California research credits carry forward indefinitely. As of December 31, 2015, we had federal and state net operating loss carry-forwards of $170.2 million and $117.0 million, respectively, and federal and state research and development tax credit carry-forwards in the amount of $3.6 million and $4.0 million, respectively. The Internal Revenue Code of 1986, as amended, imposes restrictions on the utilization of net operating losses in the event of an “ownership change” of a corporation. Accordingly, a company’s ability to use net operating losses may be limited as prescribed under Internal Revenue Code Section 382 (IRC Section 382). Events which may cause limitations in the amount of the net operating losses that the Company may use in any one year include, but are not limited to, a cumulative ownership change of more than 50% over a three-year period. In the event the Company had subsequent changes in ownership, net operating losses and research and development credit carry-overs, which are reserved by the full deferred tax asset valuation allowance, could be limited and may expire unutilized. The Company believes that, based on a number of factors, it is more likely than not, that all or some portion of the deferred tax assets will not be realized; and accordingly, for the year ended December 31, 2016, the Company has provided a valuation allowance against the Company’s U.S. and U.K. net deferred tax assets. The net change in the valuation allowance for the years ended December 31, 2016, 2015 and 2014 was an increase of $7.8 million, $11.1 million and $16.4 million, respectively. The Company has adopted the accounting policy that interest and penalties recognized are classified as part of its income taxes. The following shows the changes in the gross amount of unrecognized tax benefits as of December 31, 2016 (in thousands): Balance as of December 31, 2013 $ 933 Gross amount of increases in unrecognized tax benefits for tax positions taken in current year 465 Gross amount of increases in unrecognized tax benefits for tax positions taken in prior year 1,217 Balance as of December 31, 2014 $ 2,615 Gross amount of increases in unrecognized tax benefits for tax positions taken in current year 499 Gross amount of decreases in unrecognized tax benefits for tax positions taken in prior year (1,217 ) Balance as of December 31, 2015 $ 1,897 Gross amount of increases in unrecognized tax benefits for tax positions taken in current year 538 Gross amount of increases in unrecognized tax benefits for tax positions taken in prior years 25 Balance as of December 31, 2016 $ 2,460 The Company does not anticipate that its total unrecognized tax benefits will significantly change due to settlement of examination or the expiration of statute of limitations during the next 12 months. The Company files U.S. and foreign income tax returns with varying statutes of limitations. Due to the Company’s net carry-over of unused operating losses, all years from 2003 forward remain subject to future examination by tax authorities.

Basic and Diluted Net Loss Per

Basic and Diluted Net Loss Per Share	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Basic and Diluted Net Loss Per Share	Note 12. Basic and Diluted Net Loss Per Share Basic net loss per share is computed by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period, less the weighted-average unvested common stock subject to repurchase or forfeiture as they are not deemed to be issued for accounting purposes. Diluted net loss per share is computed by giving effect to all potential shares of common stock, stock options, restricted stock units, ESPP, and stock related to the non-vested early exercised stock options, to the extent dilutive. For the periods presented, all such common stock equivalents have been excluded from diluted net loss per share as the effect to net loss per share would be anti-dilutive. The following table sets forth the computation of the Company’s basic and diluted net loss per share during the years ended December 31, 2016, 2015 and 2014 (in thousands, except per share data): Year Ended December 31, 2016 2015 2014 Numerator Net loss $ (29,309 ) $ (32,099 ) $ (48,340 ) Denominator Weighted-average common shares for basic and diluted net loss per share 72,994 70,069 66,818 Basic and diluted net loss per share $ (0.40 ) $ (0.46 ) $ (0.72 ) The following table summarizes the potentially dilutive common shares that were excluded from diluted weighted-average common shares outstanding (in thousands): Year Ended December 31, 2016 2015 2014 Shares of common stock subject to repurchase — 2 15 Shares of common stock issuable under equity incentive plans outstanding 11,726 11,475 10,897 Potential common shares excluded from diluted net loss per share 11,726 11,477 10,912

Geographic Concentrations

Geographic Concentrations	12 Months Ended
	Dec. 31, 2016
Risks And Uncertainties [Abstract]
Geographic Concentrations	Note 13. Geographic Concentrations Revenues by geographic location are based on the billing address of the customer. More than 90% of the Company’s revenues are from the U.S. for fiscal years ended December 31, 2016, 2015 and 2014. No other individual country exceeded 10% of total revenues for fiscal years ended December 31, 2016, 2015 and 2014. Long-lived assets by geographic location is based on the location of the legal entity that owns the asset. At December 31, 2016 and 2015, more than 87% and 86% of the Company’s long-lived assets were located in the U.S., respectively, with no single country outside of the U.S. representing more than 10% of the Company’s consolidated long-lived assets.

401 (k) Plan

401 (k) Plan	12 Months Ended
	Dec. 31, 2016
Compensation And Retirement Disclosure [Abstract]
401 (k) Plan	Note 14. 401(k) Plan The Company has a qualified defined contribution plan under Section 401(k) of the Internal Revenue Code covering eligible employees. The Company did not make any matching contributions to this plan for the years ended December 31, 2016, 2015, and 2014.

Selected Quarterly Financial Da

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data (Unaudited)	Note 15. Selected Quarterly Financial Data (unaudited) The following tables set forth selected unaudited quarterly consolidated statements of operations data for each of the eight quarters in the years ended December 31, 2016 and 2015 (in thousands except per share data): Quarter ended Dec 31, Sept 30, 2016 June 30, 2016 Mar 31, 2016 Dec 31, 2015 Sept 30, 2015 June 30, 2015 Mar 31, 2015 Consolidated Statements of Operations Data Revenues $ 104,503 $ 96,839 $ 91,844 $ 86,538 $ 83,439 $ 76,780 $ 70,691 $ 65,318 Gross profit 79,851 73,384 69,480 64,798 60,577 54,447 49,162 44,771 Operating loss (6,606 ) (7,061 ) (6,304 ) (5,981 ) (5,996 ) (5,828 ) (9,539 ) (9,569 ) Net loss (6,946 ) (7,979 ) (7,771 ) (6,613 ) (6,941 ) (6,336 ) (8,211 ) (10,611 ) Net loss per share, basic and diluted $ (0.09 ) $ (0.11 ) $ (0.11 ) $ (0.09 ) $ (0.10 ) $ (0.09 ) $ (0.12 ) $ (0.15 )

Related-Party Transactions

Related-Party Transactions	12 Months Ended
	Dec. 31, 2016
Related Party Transactions [Abstract]
Related-Party Transactions	Note 16. Related-Party Transactions In the ordinary course of business, the Company made purchases from Alphabet Inc., the parent company of Google Inc., at which one of the Company’s directors serves as a Vice President of Google, Inc. Total payables to Alphabet at December 31, 2016 and 2015 were $1.0 million and $2.0 million, respectively. Total expenses incurred from Alphabet in 2016, 2015, and 2014 were $14.2 million, $11.9 million, and $10.1 million, respectively.

Subsequent Event

Subsequent Event	12 Months Ended
	Dec. 31, 2016
Subsequent Events [Abstract]
Subsequent Event	Note 17. Subsequent Event On February 10, 2017, the Company paid off its 2013 Term Loan and revolving line of credit balances of $3.4 million and $10.8 million, respectively to SVB. Upon repayment, the SVB Agreement was terminated.

Description of Business and S26

Description of Business and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Public Offerings	Public Offerings On October 2, 2013, the Company completed an initial public offering (IPO) and sold 8,625,000 shares of Class A common stock to the public, including the underwriters’ overallotment option of 1,125,000 shares of Class A common stock and 80,000 shares of Class A common stock sold by selling stockholders, at a price of $13.00 per share. The offer and sale of all of the shares in the IPO were registered under the Securities Act pursuant to a registration statement on Form S-1 (File No. 333-190815) (the Initial Registration Statement). The Company received aggregate proceeds of $103.3 million from the IPO, net of underwriters’ discounts and commissions, but before deduction of offering expenses of approximately $3.9 million. On March 11, 2014, the Company completed a secondary public offering and sold 7,991,551 shares of Class A common stock to the public, including 791,551 of the underwriters’ overallotment option and 5,200,000 shares of Class A common stock sold by selling stockholders, at a price of $21.50 per share. The offer and sale of all of the shares in the secondary public offering were registered under the Securities Act pursuant to a registration statement on Form S-1 (File No. 333-194132) (Secondary Registration Statement). The Company received aggregate proceeds of $57.2 million from the secondary public offering, net of underwriters’ discounts and commissions, but before deduction of offering expenses of approximately $1.1 million. The Company did not receive any proceeds from the sale of shares by the selling stockholders.
Principles of Consolidation	Principles of Consolidation The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) and include the consolidated accounts of the Company and its wholly-owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. The significant estimates made by management affect revenues, the allowance for doubtful accounts, inventory reserves, goodwill, share-based compensation, capitalization of internally developed software, return reserves, provision for income taxes, uncertain tax positions, loss contingencies, sales tax liabilities and accrued liabilities. Management periodically evaluates these estimates and will make adjustments prospectively based upon the results of such periodic evaluations. Actual results could differ from these estimates.
Foreign Currency	Foreign Currency The functional currency of the Company’s foreign subsidiaries is generally the local currency. Adjustments resulting from translating foreign functional currency financial statements into U.S. dollars are recorded as part of a separate component of stockholders’ equity and reported in the statements of comprehensive loss. Foreign currency transaction gains and losses are included in net loss for the period. All assets and liabilities denominated in a foreign currency are translated into U.S. dollars at the exchange rate on the balance sheet date. Revenues and expenses are translated at the average exchange rate during the period. Equity transactions are translated using historical exchange rates.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. Cash and cash equivalents are stated at fair value.
Allowance for Doubtful Accounts	Allowance for Doubtful Accounts For the years ended December 31, 2016 and 2015, a significant portion of revenues were realized from credit card transactions while the remaining revenues generated accounts receivable. The Company determines provisions based on historical loss patterns, the number of days that billings are past due, and an evaluation of the potential risk of loss associated with delinquent accounts. Below is a summary of the changes in allowance for doubtful accounts for the years ended December 31, 2016, 2015 and 2014 (in thousands): Balance at beginning of year Provision, net of recoveries Write-offs Balance at end of year Year ended December 31, 2016 Allowance for doubtful accounts $ 377 $ 648 $ 591 $ 434 Year ended December 31, 2015 Allowance for doubtful accounts $ 125 $ 411 $ 159 $ 377 Year ended December 31, 2014 Allowance for doubtful accounts $ 139 $ 40 $ 54 $ 125
Inventory	Inventory The Company’s inventory consists primarily of phones held at third parties. Inventory is stated at the lower of cost computed on a first-in, first-out basis, or market value. Inventory write-downs are recorded when the cost of inventory exceeds its net realizable value and establishes a new cost basis for the inventory. On a quarterly and annual basis, the Company analyzes inventory on a part by part basis in comparison to forecasted demand to identify potential excess and obsolescence issues, and adjusts carrying amounts to estimated net realizable value accordingly.
Internal-Use Software Development Costs	Internal-Use Software Development Costs The Company capitalizes qualifying internal-use software development costs that are incurred during the application development stage, provided that management with the relevant authority authorizes and commits to the funding of the project, it is probable the project will be completed, and the software will be used to perform the function intended. Costs related to preliminary project activities and post implementation activities are expensed as incurred. Capitalized internal-use software development costs are included in property and equipment and are amortized on a straight-line basis over their estimated useful lives. For the years ended December 31, 2016 and 2015, the Company capitalized $2.5 million and $2.1 million, net of impairment, of internal-use software development costs, respectively. The carrying value of internal-use software development costs was $4.4 million and $2.6 million at December 31, 2016 and 2015, respectively.
Property and Equipment, Net	Property and Equipment, net Property and equipment, net is stated at cost, less accumulated depreciation and amortization. Depreciation and amortization is calculated on a straight-line basis over the estimated useful lives of those assets as follows: Computer hardware and software 3 to 5 years Internal-use software development costs 3 to 4 years Furniture and fixtures 1 to 5 years Leasehold improvements Shorter of the estimated lease term or useful life The Company evaluates the recoverability of property and equipment for possible impairment whenever events or circumstances indicate that the carrying amount of such assets or asset groups may not be recoverable. Recoverability of these assets or asset groups is measured by comparing the carrying amounts of such assets or asset groups to the future undiscounted cash flows that such assets or asset groups are expected to generate. If this evaluation indicates that the carrying amount of the assets or asset groups is not recoverable, the carrying amount of such assets or asset groups is reduced to its estimated fair value. Maintenance and repairs are charged to expense as incurred.
Concentrations of Credit Risk and Significant Customers	Concentrations of Credit Risk and Significant Customers Financial instruments that subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents and accounts receivable. Although the Company deposits its cash with multiple financial institutions, its deposits, at times, may exceed federally insured limits. The Company’s accounts receivable are primarily derived from sales by resellers and to larger direct customers. The Company performs ongoing credit evaluations of its resellers and does not require collateral on accounts receivable. The Company maintains an allowance for doubtful accounts for estimated potential credit losses. At December 31, 2016 and 2015, AT&T, one of our resellers, accounted for 30% and 39% of the Company’s total accounts receivable, respectively. For the years ended December 31, 2016, 2015, and 2014, AT&T accounted for 14%, 13%, and 12% of the Company’s total revenues and 13%, 12%, and 11% of the Company’s software subscription revenues, respectively. During the years ended December 31, 2016, 2015 and 2014, the Company contracted a significant portion of its software development efforts from third-party vendors located in Russia and Ukraine. A cessation of services provided by these vendors could result in a disruption to the Company’s research and development efforts.
Revenue Recognition	Revenue Recognition The Company’s revenues consist primarily of software subscriptions and other revenues. The Company’s software subscriptions revenue includes all fees billed in connection with subscriptions to the Company’s RingCentral Office, RingCentral Professional, RingCentral Fax, RingCentral Contact Center, and RingCentral Glip products. These software subscription fees include recurring fixed plan subscription fees, variable usage-based fees for usage in excess of plan limits, recurring administrative cost recovery fees, one-time fees, and other recurring fees related to our subscriptions. The Company provides its subscriptions pursuant to contractual arrangements that range in duration from one month to three years. The Company’s subscription fees are generally billed in advance directly to customer credit cards or via invoices issued to larger customers. The Company’s other revenues consist of commission revenues earned as an agent of Westcon, product revenues from sales of phones not sold under the sales agency agreement with Westcon, phone sales to carrier partners, phone rentals, and professional implementation services. The Company recognizes revenue when the following criteria are met: • there is persuasive evidence of an arrangement; • the subscription is being provided to the customer or the product has been delivered; • the amount of fees to be paid by the customer is fixed or determinable; and • the collection of the fees is reasonably assured. Revenue under subscription plans are recognized as follows: • fixed plan subscription and administrative cost recovery fees are recognized on a straight-line basis over their respective contractual subscription terms; • fees for additional minutes of usage in excess of plan limits are recognized over the estimated usage period in a manner that approximates actual usage; and • one-time upfront fees are initially deferred and recognized on a straight-line basis over the estimated average customer life. Commission revenue is recognized when services have been rendered. Product revenue is billed at the time the order is received and recognized when the phone has been delivered to the customer. Professional service revenue is recognized upon completion of performance. The Company enters into arrangements with multiple-elements that generally include services to be provided under the subscription plan and the sale of products used in connection with the Company’s subscriptions. The Company allocates the consideration to each deliverable in a multiple-deliverable arrangement based upon its relative selling prices. The Company determines the selling price using vendor-specific objective evidence (VSOE) for its subscription plans and best estimated selling price (BESP) for its product offerings. Consideration allocated to each deliverable, limited to the amount not contingent on future performance, is then recognized to revenue when the basic revenue recognition criteria are met for the respective deliverable. The Company determines VSOE based on historical standalone sales to customers. In determining VSOE, the Company requires that a substantial majority of the selling prices fall within a reasonably narrow pricing range. VSOE exists for all of the Company’s subscription plans. The Company uses BESP as the selling price for its product offerings as the Company is not able to determine VSOE of fair value from standalone sales or third-party evidence of selling price (TPE). The Company estimates BESP for a product by considering company-specific factors such as pricing objectives, direct product and other costs, bundling and discounting practices, and contractually stated prices. A portion of the Company’s software subscriptions and product revenues are generated through sales by resellers. When the Company assumes a majority of the business risks associated with performance of the contractual obligations, it records these revenues at the gross amount paid by the customer with amounts retained by the resellers recognized as sales and marketing expense. The Company’s assumption of such business risks is evidenced when, among other things, it takes responsibility for delivery of the product or subscription, is involved in establishing pricing of the arrangement, assumes credit and inventory risk, and is the primary obligor in the arrangement. When a reseller assumes the majority of the business risks associated with the performance of the contractual obligations, the Company records the associated revenue at the net amount received from the reseller. The Company recognizes revenue from resellers when the following criteria are met: • persuasive evidence of an arrangement exists through a contract with the customer; • the subscription is being provided to the customer or the product has been delivered; • the amount of fees to be paid by the customer is fixed or determinable; and • the collection of the fees is reasonably assured. The Company’s deliverables sold through its reseller agreements consist of the Company’s software subscriptions and products. Subscriptions sold through resellers are recognized on a straight-line basis over the period the subscriptions are provided to the end customer. Phones sold through resellers are shipped directly to the end customer and are recognized when title transfers to the end customer. Revenue from resellers has predominantly been recorded on a gross basis for all periods presented. The Company records reductions to revenue for estimated sales returns and customer credits at the time the related revenue is recognized. Sales returns and customer credits are estimated based on historical experience, current trends, and expectations regarding future experience. Customer billings related to taxes imposed by and remitted to governmental authorities on revenue-producing transactions are reported on a net basis. When such remitted taxes exceed the amount billed to customers, the cost is included in general and administrative expenses. Amounts billed in excess of revenue recognized for the period are reported as deferred revenue on the consolidated balance sheet. The Company’s deferred revenue consists primarily of unearned revenue on annual and monthly subscription plans. During the year ended December 31, 2014, the Company received one-time up-front payments for implementation services to be performed in connection with its carrier agreements with BT and TELUS. These amounts are being amortized on a straight-line basis over their respective initial contractual terms beginning in 2015. The BT and TELUS arrangements have initial contractual terms of three to five years, which approximates the estimated average customer life of each respective agreement. Accordingly, the portion of these one-time up-front payments that is expected to be earned after December 31, 2017, or $0.4 million, is included as a component of other long-term liabilities in the consolidated balance sheets.
Cost of Revenues	Cost of Revenues Cost of software subscriptions revenue primarily consists of costs of network capacity purchased from third-party telecommunications providers, network operations, costs to build out and maintain data centers, including co-location fees for the right to place the Company’s servers in data centers owned by third-parties, depreciation of the servers and equipment, along with related utilities and maintenance costs, personnel costs associated with customer care and support of the functionality of the Company’s platform and data center operations, including share-based compensation expenses, and allocated costs of facilities and information technology. Cost of software subscriptions revenue is expensed as incurred. Cost of other revenue is comprised primarily of the cost associated with purchased phones that fell outside of the agency model, shipping costs, costs of professional services, and allocated costs of facilities and information technology related to the procurement, management and shipment of phones. Cost of other revenue is expensed in the period product is delivered to the customer.
Share-Based Compensation	Share-Based Compensation Share-based compensation expense resulting from options, restricted stock units (RSUs), and employee stock purchase plan (ESPP) rights granted is measured as the grant date fair value of the award and is recognized using the straight-line attribution method over the requisite service period of the award, which is generally the vesting period. The Company estimates the fair value of stock options and ESPP rights using the Black-Scholes-Merton option-pricing model. The Company estimates the fair value of RSUs as the closing market value of its Class A Common Stock on the grant date. Compensation expense for stock options and RSUs granted to non-employees is revalued, or marked to market, as of each reporting date until the stock options and RSUs are vested. Compensation expense is recognized net of estimated forfeiture activity, which is based on historical forfeiture rates.
Research and Development	Research and Development Research and development expenses consist primarily of third-party contractor costs, personnel costs, technology license expenses, and depreciation associated with research and development equipment. Research and development costs are expensed as incurred.
Advertising Costs	Advertising Costs Advertising costs, which include various forms of e-commerce such as search engine marketing, search engine optimization and online display advertising, as well as more traditional forms of media advertising such as radio and billboards, are expensed as incurred and were $41.6 million, $34.3 million, and $27.1 million for the years ended December 31, 2016, 2015 and 2014, respectively.
Commissions	Commissions Commissions consist of variable compensation earned by sales personnel and third-party resellers. Sales commissions associated with the acquisition of a new customer contract are recognized as sales and marketing expense at the time the customer has entered into a binding agreement.
Income Taxes	Income Taxes The Company accounts for income taxes using the asset and liability method. Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis. Deferred tax assets and liabilities are measured using enacted tax rates in effect for the year in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in operations in the period that includes the enactment date. The Company records a valuation allowance to reduce its deferred tax assets to the amount of future tax benefit that is more likely than not to be realized. As of December 31, 2016, except for deferred tax assets associated with its subsidiaries in the Netherlands and China, the Company recorded a full valuation allowance against all other net deferred tax assets due to its history of operating losses. The Company classifies interest and penalties on unrecognized tax benefits as income tax expense.
Segment Information	Segment Information The Company has determined the chief executive officer is the chief operating decision maker. The Company’s chief executive officer reviews financial information presented on a consolidated basis for purposes of assessing performance and making decisions on how to allocate resources. Accordingly, the Company has determined that it operates in a single reportable segment.
Indemnification	Indemnification Certain of the Company’s agreements with resellers and customers include provisions for indemnification against liabilities if its subscriptions infringe upon a third-party’s intellectual property rights. At least quarterly, the Company assesses the status of any significant matters and its potential financial statement exposure. If the potential loss from any claim or legal proceeding is considered probable and the amount or the range of loss can be estimated, the Company accrues a liability for the estimated loss. The Company has not incurred any material costs as a result of such indemnification provisions and the Company has not accrued any liabilities related to such obligations in the consolidated financial statements as of December 31, 2016 or 2015.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2014-09, Revenue from Contracts with Customers (Topic 606), In addition, the standard requires disclosure of the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. The Company is currently evaluating the potential changes from adopting the new standard on its financial statements and disclosures. The Company is in the process of implementing appropriate changes to its business processes, systems and controls to support revenue recognition and disclosures under the new standard. Based on this evaluation, the Company will adopt the requirements of the new standard in the first quarter of 2018 and anticipates using the modified retrospective transition method. Additionally, as the Company continues to assess the new standard along with industry trends and internal progress, the Company may adjust its implementation plan accordingly. Under the new standard, the Company expects to capitalize certain sales commission costs and in some cases recognize revenue earlier for subscription plans with free periods and products sold at discounts. The impact of adopting the new standard on the Company’s total revenues is not expected to be material. However, the Company anticipates the most significant impacts of adopting the new standard primarily relates to the deferral of sales commissions, which previously were expensed as incurred and to the incremental disclosure requirements. Under the new standard, certain commissions will be capitalized and amortized over the expected period of benefit. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) In March 2016, the FASB issued ASU 2016-09, Compensation-Stock Compensation: Improvements to Employee Share-Based Payment Accounting (Topic 718) In August 2016, the FASB issued ASU 2016-15, Classification of Certain Cash Receipts and Cash Payments In October 2016, the FASB issued ASU 2016-16, Intra-Entity Transfers of Assets Other Than Inventory In November 2016, the FASB issued ASU 2016-18, Restricted Cash
Reclassification	Reclassification Certain immaterial items previously reported have been reclassified to conform to the current year’s reporting presentation.

Description of Business and S27

Description of Business and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Changes in Allowance for Doubtful Accounts	Below is a summary of the changes in allowance for doubtful accounts for the years ended December 31, 2016, 2015 and 2014 (in thousands): Balance at beginning of year Provision, net of recoveries Write-offs Balance at end of year Year ended December 31, 2016 Allowance for doubtful accounts $ 377 $ 648 $ 591 $ 434 Year ended December 31, 2015 Allowance for doubtful accounts $ 125 $ 411 $ 159 $ 377 Year ended December 31, 2014 Allowance for doubtful accounts $ 139 $ 40 $ 54 $ 125
Estimated Useful Lives of Assets	Depreciation and amortization is calculated on a straight-line basis over the estimated useful lives of those assets as follows: Computer hardware and software 3 to 5 years Internal-use software development costs 3 to 4 years Furniture and fixtures 1 to 5 years Leasehold improvements Shorter of the estimated lease term or useful life

Financial Statement Components

Financial Statement Components (Tables)	12 Months Ended
	Dec. 31, 2016
Statement Of Financial Position [Abstract]
Components of Cash and Cash Equivalents	Cash and cash equivalents consisted of the following (in thousands): December 31, December 31, 2016 2015 Cash $ 40,908 $ 18,522 Money market funds 119,447 119,066 Total cash and cash equivalents $ 160,355 $ 137,588
Components of Accounts Receivable, Net	Accounts receivable, net consisted of the following (in thousands): December 31, December 31, 2016 2015 Accounts receivable $ 26,731 $ 15,509 Unbilled accounts receivable 3,946 4,031 Allowance for doubtful accounts (434 ) (377 ) Accounts receivable, net $ 30,243 $ 19,163
Components of Property and Equipment, Net	Property and equipment, net consisted of the following (in thousands): December 31, December 31, 2016 2015 Computer hardware and software $ 61,546 $ 49,774 Internal-use software development costs 9,931 7,432 Furniture and fixtures 4,508 3,610 Leasehold improvements 2,596 2,412 Property and equipment, gross 78,581 63,228 Less: accumulated depreciation and amortization (46,587 ) (35,068 ) Property and equipment, net $ 31,994 $ 28,160
Components of Accrued Liabilities	Accrued liabilities consisted of the following (in thousands): December 31, December 31, 2016 2015 Accrued compensation and benefits $ 14,041 $ 10,128 Accrued sales, use, and telecom related taxes 7,220 5,243 Accrued marketing 5,082 3,930 Other accrued expenses 21,979 15,401 Total accrued liabilities $ 48,322 $ 34,702

Fair Value of Financial Instr29

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Financial Assets Carried at Fair Value	The financial assets carried at fair value were determined using the following inputs (in thousands): Balance at December 31, (Level 1) (Level 2) (Level 3) Cash equivalents: Money market funds $ 119,447 $ 119,447 $ — $ — Other assets: Certificates of deposit $ 530 $ — $ 530 $ — Balance at December 31, (Level 1) (Level 2) (Level 3) Cash equivalents: Money market funds $ 119,066 $ 119,066 $ — $ — Other assets: Certificates of deposit $ 530 $ — $ 530 $ —

Business Combinations (Tables)

Business Combinations (Tables)	12 Months Ended
	Dec. 31, 2016
Summary of Consideration Exchanged	The consideration exchanged consisted of the following (in thousands): Cash, net of cash acquired $ 4,670 Common stock issued (223,190 shares) 3,447 Holdback based on standard representations and warranties 1,500 Total initial consideration 9,617 Milestone based earn out 2,289 Total consideration $ 11,906
Summary of Fair Value of Assets Acquired	The following table summarizes the fair value of assets acquired as of the date of acquisition (in thousands): Cash and cash equivalents $ 74 Acquired intangible assets 3,850 Goodwill 7,982 Net assets acquired $ 11,906
Summary of Fair Value Components of Identifiable Acquired Intangible Assets and Their Estimated Useful Lives	The following table sets forth the fair value components of identifiable acquired intangible assets (in thousands) and their estimated useful lives (in years) as of the date of acquisition: Fair Value Estimated Useful Life Customer relationships $ 840 2 years Developed technology 3,010 5 years Total identifiable acquired intangible assets subject to amortization $ 3,850
Summary of Carrying Values of Intangible Assets	The carrying values of intangible assets at December 31, 2016 and 2015 are as follows (in thousands): December 31, 2016 December 31, 2015 Estimated Lives Cost Accumulated Amortization Acquired Intangibles, Net Accumulated Amortization Acquired Intangibles, Net Customer relationships 2 years $ 840 $ 660 $ 180 $ 240 $ 600 Developed technology 5 years 3,010 946 2,064 344 2,666 Total acquired intangible assets $ 3,850 $ 1,606 $ 2,244 $ 584 $ 3,266
Glip, Inc.
Summary of Estimated Amortization Expense for Acquired Intangible Assets	Estimated amortization expense for acquired intangible assets for the following five fiscal years and thereafter is as follows (in thousands): 2017 $ 782 2018 602 2019 602 2020 258 2021 — Total estimated amortization expense $ 2,244

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Schedule of Future Debt Principal Payments	As of December 31, 2016, future debt principal payments are scheduled as follows (in thousands): 2017 $ 14,528 2018 312 Total future repayments of debt $ 14,840

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2016
Commitments And Contingencies Disclosure [Abstract]
Schedule of Future Minimum Lease Payments for Capital and Operating Leases	As of December 31, 2016, non-cancelable leases expire on various dates between 2017 and 2021 and require the following future minimum lease payments by year (in thousands): Capital Leases Operating Leases Year ending December 31, 2017 $ 185 $ 7,281 2018 — 7,164 2019 — 5,945 2020 — 3,451 2021 — 2,131 Total future minimum lease payments $ 185 $ 25,972 Less: amount representing interest (4 ) Total capital lease obligation $ 181
Property and Equipment Recorded Under Capital Leases	Property and equipment recorded under capital leases consisted of the following (in thousands): December 31, 2016 2015 Property and equipment acquired under capital lease $ 3,149 $ 3,149 Less: accumulated amortization (2,600 ) (2,212 ) Property and equipment acquired under capital lease, net $ 549 $ 937

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Summary of Common Stock Reserved for Future Issuance	Shares of Class A common stock reserved for future issuance were as follows (in thousands): December 31, 2016 Preferred stock 100,000 Class B common stock 13,091 2013 Employee stock purchase plan 2,292 2013 Equity incentive plan: Outstanding options and restricted stock unit awards 10,938 Available for future grants 8,703 135,024

Share-Based Compensation (Table

Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Share-Based Compensation Expense Recognized to Statements of Operations	A summary of share-based compensation expense recognized in the Company’s consolidated statements of operations is as follows (in thousands): Year Ended December, 31 2016 2015 2014 Cost of revenues $ 3,165 $ 2,054 $ 1,294 Research and development 7,296 5,387 3,343 Sales and marketing 10,902 7,200 5,260 General and administrative 9,477 7,447 5,619 Total share-based compensation expense $ 30,840 $ 22,088 $ 15,516
Summary of Share-Based Compensation Expense by Award Type	A summary of share-based compensation expense by award type is as follows (in thousands): Year Ended December, 31 2016 2015 2014 Options $ 9,626 $ 11,170 $ 10,323 Employee stock purchase plan rights 1,737 1,365 1,628 Restricted stock units 19,477 9,553 3,565 Total share-based compensation expense $ 30,840 $ 22,088 $ 15,516
Summary of Stock Option Activity Plans	A summary of option activity under all of the plans at December 31, 2016 and changes during the periods then ended is presented in the following table: Weighted- Number of Weighted- Average Aggregate Options Average Contractual Intrinsic Outstanding Exercise Price Term Value (in thousands) Per Share (in Years) (in thousands) Outstanding at December 31, 2013 11,156 $ 5.87 7.7 $ 139,484 Granted 1,302 15.12 Exercised (2,673 ) 1.97 Canceled/Forfeited (627 ) 7.19 Outstanding at December 31, 2014 9,158 $ 8.23 7.2 $ 61,367 Granted 1,881 16.35 Exercised (2,323 ) 6.82 Canceled/Forfeited (668 ) 11.42 Outstanding at December 31, 2015 8,048 $ 10.27 6.2 $ 107,091 Granted 547 16.53 Exercised (962 ) 10.01 Canceled/Forfeited (249 ) 15.50 Outstanding at December 31, 2016 7,384 $ 10.59 5.3 $ 74,065 Vested and expected to vest as of December 31, 2016 7,083 $ 10.36 5.3 $ 72,684 Exercisable as of December 31, 2016 5,359 $ 8.68 5.1 $ 63,893
Schedule of Total Intrinsic Values of Options Exercised	The total intrinsic values of options exercised during the years ended December31, 2016, 2015, and 2014 were as follows (in thousands): Year Ended December 31, 2016 2015 2014 Total intrinsic value of options exercised $ 10,718 $ 28,336 $ 41,454
Weighted Average Assumptions Used to Fair Value of Stock Options Granted	The weighted-average assumptions used in the option-pricing model and the resulting grant date fair value of stock options granted in the periods presented were as follows: Year ended December 31, 2016 2015 2014 Expected term for employees (in years) 4.7 4.8 4.6 Expected term for non-employees (in years) 5.9 7.1 7.0 Expected volatility 47 % 48 % 48 % Risk-free interest rate 1.12 % 1.22 % 1.41 % Expected dividend yield 0 % 0 % 0 % Grant date fair value of employee options $ 6.72 $ 6.78 $ 6.16
Summary of Assumptions Used to Value ESPP Rights Under the Black-Scholes Option-Pricing Model	The weighted-average assumptions used to value ESPP rights under the Black-Scholes-Merton option-pricing model and the resulting offering grant date fair value of ESPP rights granted in the periods presented were as follows: Year ended December 31, 2016 2015 2014 Expected term (in years) 0.5 0.5 0.5 Expected volatility 41 % 42 % 50 % Risk-free interest rate 0.50 % 0.25 % 0.07 % Expected dividend yield 0 % 0 % 0 % Offering grant date fair value of ESPP rights $ 5.29 $ 5.05 $ 3.93
Summary of RSUs Activity	The 2013 Plan provides for the issuance of RSUs to employees and consultants. RSUs issued under the 2013 Plan generally vest over four years. A summary of activity of RSUs under the 2013 Plan at December 31, 2016 and changes during the periods then ended is presented in the following table: Number of Weighted- Aggregate RSUs Average Intrinsic Outstanding Grant Date Fair Value (in thousands) Value Per Share (in thousands) Outstanding at December 31, 2013 68 $ 17.22 $ 1,251 Granted 1,915 15.08 Released (110 ) 16.82 Canceled/Forfeited (134 ) 17.43 Outstanding at December 31, 2014 1,739 $ 14.87 $ 25,617 Granted 1,365 18.09 Released (571 ) 15.45 Canceled/Forfeited (245 ) 15.10 Outstanding at December 31, 2015 2,288 $ 16.63 $ 53,972 Granted 2,798 18.65 Released (1,096 ) 16.77 Canceled/Forfeited (436 ) 17.92 Outstanding at December 31, 2016 3,554 $ 18.01 $ 73,261

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Summary of Provision (Benefit) for Income Taxes	The provision (benefit) for income taxes consisted of the following (in thousands): Year ended December 31, 2016 2015 2014 Current Federal $ — $ — $ — State 63 71 18 Foreign 209 85 114 Total current 272 156 132 Deferred Federal $ — $ (1,312 ) $ — State — (99 ) — Foreign (36 ) (8 ) (35 ) Total deferred (36 ) (1,419 ) (35 ) Total income tax provision (benefit) $ 236 $ (1,263 ) $ 97
Summary of Net Loss Before Provision (Benefit) for Income Taxes	Net loss before provision (benefit) for income taxes consisted of the following (in thousands): Year ended December 31, 2016 2015 2014 United States $ (27,908 ) $ (28,870 ) $ (50,065 ) International (1,165 ) (4,492 ) 1,822 Total net loss before benefit for income taxes $ (29,073 ) $ (33,362 ) $ (48,243 )
Summary of Variation of Effective Provision (Benefit) for Income Taxes from Statutory Federal Income Tax Rate	The provision (benefit) for income tax differed from the amounts computed by applying the U.S. federal income tax rate of 34% to pretax loss as a result of the following (in thousands): Year ended December 31, 2016 2015 2014 Federal tax benefit at statutory rate $ (9,885 ) $ (11,343 ) $ (16,403 ) State tax, net of federal provision (benefit) 28 (34 ) 12 Research and development credits (745 ) (667 ) (654 ) Share-based compensation 960 1,086 1,836 Other permanent differences 600 325 211 Foreign tax rate differential (225 ) (80 ) (33 ) Net operating losses not recognized 9,503 10,762 15,128 Release of valuation allowance associated with acquisitions — (1,312 ) — Total income tax provision (benefit) $ 236 $ (1,263 ) $ 97
Schedule of Deferred Income Tax Assets and Liabilities	The types of temporary differences that give rise to significant portions of the Company’s deferred tax assets and liabilities are as follows (in thousands): Year ended December 31, 2016 2015 2014 Deferred tax assets Net operating loss and credit carry-forwards $ 59,863 $ 54,858 $ 45,552 Research and development credits 6,094 4,712 3,497 Sales tax liability 1,131 1,337 1,442 Share-based compensation 7,281 6,694 5,560 Accrued liabilities 6,525 6,090 4,676 Gross deferred tax assets 80,894 73,691 60,727 Valuation allowance (79,319 ) (71,514 ) (60,405 ) Total deferred tax assets 1,575 2,177 322 Deferred tax liabilities - Acquired intangibles (803 ) (1,164 ) — Deferred tax liabilities - Property and equipment (606 ) (883 ) (197 ) Net deferred tax assets $ 166 $ 130 $ 125
Summary of Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits	The Company has adopted the accounting policy that interest and penalties recognized are classified as part of its income taxes. The following shows the changes in the gross amount of unrecognized tax benefits as of December 31, 2016 (in thousands): Balance as of December 31, 2013 $ 933 Gross amount of increases in unrecognized tax benefits for tax positions taken in current year 465 Gross amount of increases in unrecognized tax benefits for tax positions taken in prior year 1,217 Balance as of December 31, 2014 $ 2,615 Gross amount of increases in unrecognized tax benefits for tax positions taken in current year 499 Gross amount of decreases in unrecognized tax benefits for tax positions taken in prior year (1,217 ) Balance as of December 31, 2015 $ 1,897 Gross amount of increases in unrecognized tax benefits for tax positions taken in current year 538 Gross amount of increases in unrecognized tax benefits for tax positions taken in prior years 25 Balance as of December 31, 2016 $ 2,460

Basic and Diluted Net Loss Pe36

Basic and Diluted Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Computation of Company's Basic and Diluted Net Loss Per Share of Common Stock	The following table sets forth the computation of the Company’s basic and diluted net loss per share during the years ended December 31, 2016, 2015 and 2014 (in thousands, except per share data): Year Ended December 31, 2016 2015 2014 Numerator Net loss $ (29,309 ) $ (32,099 ) $ (48,340 ) Denominator Weighted-average common shares for basic and diluted net loss per share 72,994 70,069 66,818 Basic and diluted net loss per share $ (0.40 ) $ (0.46 ) $ (0.72 )
Potential Shares of Common Stock Excluded from Diluted Weighted-Average Common Shares Outstanding	The following table summarizes the potentially dilutive common shares that were excluded from diluted weighted-average common shares outstanding (in thousands): Year Ended December 31, 2016 2015 2014 Shares of common stock subject to repurchase — 2 15 Shares of common stock issuable under equity incentive plans outstanding 11,726 11,475 10,897 Potential common shares excluded from diluted net loss per share 11,726 11,477 10,912

Selected Quarterly Financial 37

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Selected Unaudited Quarterly Consolidated Statements of Operations Data	The following tables set forth selected unaudited quarterly consolidated statements of operations data for each of the eight quarters in the years ended December 31, 2016 and 2015 (in thousands except per share data): Quarter ended Dec 31, Sept 30, 2016 June 30, 2016 Mar 31, 2016 Dec 31, 2015 Sept 30, 2015 June 30, 2015 Mar 31, 2015 Consolidated Statements of Operations Data Revenues $ 104,503 $ 96,839 $ 91,844 $ 86,538 $ 83,439 $ 76,780 $ 70,691 $ 65,318 Gross profit 79,851 73,384 69,480 64,798 60,577 54,447 49,162 44,771 Operating loss (6,606 ) (7,061 ) (6,304 ) (5,981 ) (5,996 ) (5,828 ) (9,539 ) (9,569 ) Net loss (6,946 ) (7,979 ) (7,771 ) (6,613 ) (6,941 ) (6,336 ) (8,211 ) (10,611 ) Net loss per share, basic and diluted $ (0.09 ) $ (0.11 ) $ (0.11 ) $ (0.09 ) $ (0.10 ) $ (0.09 ) $ (0.12 ) $ (0.15 )

Description of Business and S38

Description of Business and Summary of Significant Accounting Policies - Additional Information (Detail) $ / shares in Units, $ in Thousands	Dec. 31, 2014	Mar. 11, 2014USD ($)$ / sharesshares	Oct. 02, 2013USD ($)$ / sharesshares	Dec. 31, 2016USD ($)Segment	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Deferred offering costs						$ 1,219
Proceeds from issuance of common stock						57,167
Software development cost, net of impairment				$ 2,500	$ 2,100
Internal-use software development costs				4,400	2,600
Advertising Expense				$ 41,600	$ 34,300	$ 27,100
Number of reportable segment | Segment				1
TELUS And British Telecom
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
One time upfront payment				$ 400
Minimum
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Contractual arrangement subscriptions period				1 month
Minimum | TELUS And British Telecom
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
TELUS and BT transaction agreement initial, term years				3 years
Maximum
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Contractual arrangement subscriptions period				3 years
Maximum | TELUS And British Telecom
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
TELUS and BT transaction agreement initial, term years				5 years
Accounts receivable | Customer concentration risk
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage				30.00%	39.00%
Revenues | Customer concentration risk
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	12.00%			14.00%	13.00%
Software subscription revenues | Customer concentration risk
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	11.00%			13.00%	12.00%
Class A common stock | Initial Public Offering
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Common stock, shares issued | shares			8,625,000
Sale of stock, price per share | $ / shares			$ 13
Proceeds from issuance of initial public offering			$ 103,300
Deferred offering costs			$ 3,900
Class A common stock | Secondary Public Offering
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Common stock, shares issued | shares		7,991,551
Sale of stock, price per share | $ / shares		$ 21.50
Deferred offering costs		$ 1,100
Proceeds from issuance of common stock		$ 57,200
Overallotment Option | Class A common stock | Initial Public Offering
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Common stock, shares issued | shares			1,125,000
Overallotment Option | Class A common stock | Secondary Public Offering
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Common stock, shares issued | shares		791,551
Selling Stockholders | Class A common stock | Initial Public Offering
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Common stock, shares issued | shares			80,000
Selling Stockholders | Class A common stock | Secondary Public Offering
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Common stock, shares issued | shares		5,200,000

Description of Business and S39

Description of Business and Summary of Significant Accounting Policies - Changes in Allowance for Doubtful Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Receivables [Abstract]
Balance at beginning of year	$ 377	$ 125	$ 139
Provision, net of recoveries	648	411	40
Write-offs	591	159	54
Balance at end of year	$ 434	$ 377	$ 125

Description of Business and S40

Description of Business and Summary of Significant Accounting Policies - Estimated Useful Lives of Assets (Detail)	12 Months Ended
	Dec. 31, 2016
Computer hardware and software | Minimum
Property Plant And Equipment [Line Items]
Estimated useful lives	3 years
Computer hardware and software | Maximum
Property Plant And Equipment [Line Items]
Estimated useful lives	5 years
Internal-use software development costs | Minimum
Property Plant And Equipment [Line Items]
Estimated useful lives	3 years
Internal-use software development costs | Maximum
Property Plant And Equipment [Line Items]
Estimated useful lives	4 years
Furniture and fixtures | Minimum
Property Plant And Equipment [Line Items]
Estimated useful lives	1 year
Furniture and fixtures | Maximum
Property Plant And Equipment [Line Items]
Estimated useful lives	5 years
Leasehold improvements
Property Plant And Equipment [Line Items]
Estimated useful lives	Shorter of the estimated lease term or useful life

Change in Presentation - Additi

Change in Presentation - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Product revenues	$ 13.3	$ 23.3	$ 19.2
Product cost of revenues	$ 15.8	$ 20.3	$ 17.9

Financial Statement Component42

Financial Statement Components - Components of Cash and Cash Equivalents (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash And Cash Equivalents [Abstract]
Cash	$ 40,908	$ 18,522
Money market funds	119,447	119,066
Total cash and cash equivalents	$ 160,355	$ 137,588	$ 113,182	$ 116,378

Financial Statement Component43

Financial Statement Components - Components of Accounts Receivable, Net (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Receivables [Abstract]
Accounts receivable	$ 26,731	$ 15,509
Unbilled accounts receivable	3,946	4,031
Allowance for doubtful accounts	(434)	(377)	$ (125)	$ (139)
Accounts receivable, net	$ 30,243	$ 19,163

Financial Statement Component44

Financial Statement Components - Components of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 78,581	$ 63,228
Less: accumulated depreciation and amortization	(46,587)	(35,068)
Property and equipment, net	31,994	28,160
Computer hardware and software
Property Plant And Equipment [Line Items]
Property and equipment, gross	61,546	49,774
Internal-use software development costs
Property Plant And Equipment [Line Items]
Property and equipment, gross	9,931	7,432
Furniture and fixtures
Property Plant And Equipment [Line Items]
Property and equipment, gross	4,508	3,610
Leasehold improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 2,596	$ 2,412

Financial Statement Component45

Financial Statement Components - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property Plant And Equipment [Line Items]
Depreciation and amortization	$ 14,663	$ 13,467	$ 10,378
Property and equipment
Property Plant And Equipment [Line Items]
Depreciation and amortization	$ 13,600	$ 12,900	$ 10,400

Financial Statement Component46

Financial Statement Components - Components of Accrued Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Payables And Accruals [Abstract]
Accrued compensation and benefits	$ 14,041	$ 10,128
Accrued sales, use, and telecom related taxes	7,220	5,243
Accrued marketing	5,082	3,930
Other accrued expenses	21,979	15,401
Total accrued liabilities	$ 48,322	$ 34,702

Fair Value of Financial Instr47

Fair Value of Financial Instruments - Financial Assets Carried at Fair Value (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Money market funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Money market funds	$ 119,447	$ 119,066
Money market funds | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Money market funds	119,447	119,066
Certificates of deposit
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Certificates of deposit	530	530
Certificates of deposit | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Certificates of deposit	$ 530	$ 530

Fair Value of Financial Instr48

Fair Value of Financial Instruments - Additional Information (Detail) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Fair value of debt obligation	$ 14.9	$ 19
Carrying value of debt obligation	$ 14.8	$ 18.6

Business Combinations - Additio

Business Combinations - Additional Information (Detail) - USD ($)	1 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Business combination, contingent consideration paid in full			$ 1,500,000
Glip, Inc.
Business Acquisition [Line Items]
Business combination, consideration payable in combination of cash and common stock		$ 11,906,000
Business combination, fair value of milestone based earn out liability		2,289,000		$ 2,400,000
Business combination, fair value of milestone based earn out liability, current			1,900,000
Business combination contingent consideration maximum potential cash payment			$ 2,000,000
Business combination earn out period of contingent consideration			2 years
Business combination, contingent payment liability			$ 1,400,000	600,000
Amortization expense of Intangible Assets			$ 1,100,000	$ 600,000
Glip, Inc. | Customer Relationships
Business Acquisition [Line Items]
Weighted-average amortization periods			4 months 24 days
Glip, Inc. | Developed Technology
Business Acquisition [Line Items]
Weighted-average amortization periods			3 years 4 months 24 days
Glip, Inc. | Class A common stock
Business Acquisition [Line Items]
Business combination, consideration common stock issued			45,893
Glip, Inc. | Common Stock
Business Acquisition [Line Items]
Business combination, fair value of consideration shares net amount		$ 3,447,000
Business combination, consideration common stock issued		223,190
Business combination, consideration shares gross amount		$ 3,800,000
Business combination, consideration shares marketability discount		400,000
Glip, Inc. | Asset purchase agreement
Business Acquisition [Line Items]
Business combination, contingent consideration paid in full	$ 1,500,000
Business combination, fair value of milestone based earn out liability		$ 1,500,000

Business Combinations - Summary

Business Combinations - Summary of Consideration Exchanged (Detail) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2015
Business Acquisition [Line Items]
Cash, net of cash acquired		$ 4,670
Glip, Inc.
Business Acquisition [Line Items]
Cash, net of cash acquired	$ 4,670
Holdback based on standard representations and warranties	1,500
Total initial consideration	9,617
Milestone based earn out	2,289	$ 2,400
Total consideration	11,906
Common Stock | Glip, Inc.
Business Acquisition [Line Items]
Common stock issued (223,190 shares)	$ 3,447

Business Combinations - Summa51

Business Combinations - Summary of Consideration Exchanged (Parenthetical) (Detail)	1 Months Ended
	Jun. 30, 2015shares
Glip, Inc. | Common Stock
Business Acquisition [Line Items]
Business combination, consideration common stock issued	223,190

Business Combinations - Summa52

Business Combinations - Summary of Fair Value of Assets Acquired (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Jun. 30, 2015
Business Acquisition [Line Items]
Goodwill	$ 9,393	$ 9,393
Glip, Inc.
Business Acquisition [Line Items]
Cash and cash equivalents			$ 74
Acquired intangible assets			3,850
Goodwill			7,982
Net assets acquired			$ 11,906

Business Combinations - Summa53

Business Combinations - Summary of Fair Value Components of Identifiable Acquired Intangible Assets And Their Estimated Useful Lives (Detail) - Glip, Inc. - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Total identifiable acquired intangible assets subject to amortization, Fair Value	$ 3,850
Customer relationships
Business Acquisition [Line Items]
Total identifiable acquired intangible assets subject to amortization, Fair Value	$ 840
Total identifiable acquired intangible assets subject to amortization, Estimated Useful Life	2 years	2 years	2 years
Developed technology
Business Acquisition [Line Items]
Total identifiable acquired intangible assets subject to amortization, Fair Value	$ 3,010
Total identifiable acquired intangible assets subject to amortization, Estimated Useful Life	5 years	5 years	5 years

Business Combinations - Summa54

Business Combinations - Summary of Carrying Values of Intangible Assets (Detail) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Acquired Intangibles, Net		$ 2,244	$ 3,266
Glip, Inc.
Business Acquisition [Line Items]
Cost		3,850	3,850
Accumulated Amortization		1,606	584
Acquired Intangibles, Net		$ 2,244	$ 3,266
Glip, Inc. | Customer Relationships
Business Acquisition [Line Items]
Estimated Lives	2 years	2 years	2 years
Cost		$ 840	$ 840
Accumulated Amortization		660	240
Acquired Intangibles, Net		$ 180	$ 600
Glip, Inc. | Developed Technology
Business Acquisition [Line Items]
Estimated Lives	5 years	5 years	5 years
Cost		$ 3,010	$ 3,010
Accumulated Amortization		946	344
Acquired Intangibles, Net		$ 2,064	$ 2,666

Business Combinations - Summa55

Business Combinations - Summary of Estimated Amortization Expense for Acquired Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Acquired Indefinite Lived Intangible Assets [Line Items]
Acquired Intangibles, Net	$ 2,244	$ 3,266
Glip, Inc.
Acquired Indefinite Lived Intangible Assets [Line Items]
2,017	782
2,018	602
2,019	602
2,020	258
Acquired Intangibles, Net	$ 2,244	$ 3,266

Debt - Additional Information (

Debt - Additional Information (Detail)	Apr. 30, 2016	Dec. 31, 2013USD ($)Installment	May 31, 2016	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Debt Instrument [Line Items]
Outstanding balance of term loan				$ 14,840,000
Long-term debt				312,000	$ 14,840,000
Required Cash Balances Maintained With Silicon Valley Bank | Prime Rate | Revolving Credit Facility
Debt Instrument [Line Items]
Percentage of margin	0.25%
Required Cash Balances Maintained With Silicon Valley Bank | LIBOR Rate | Revolving Credit Facility
Debt Instrument [Line Items]
Percentage of margin	3.25%
Required Cash Balances Not Maintained With Silicon Valley Bank | Prime Rate | Revolving Credit Facility
Debt Instrument [Line Items]
Percentage of margin	0.50%
Required Cash Balances Not Maintained With Silicon Valley Bank | LIBOR Rate | Revolving Credit Facility
Debt Instrument [Line Items]
Percentage of margin	3.50%
SVB Agreement | Minimum
Debt Instrument [Line Items]
Debt covenant requirement				$ 10,000,000
SVB Agreement | Revolving Credit Facility
Debt Instrument [Line Items]
Interest rate on debt				3.75%
Debt instrument, maturity, description				due in August 2017
Revolving line of credit, maximum borrowing amount				$ 15,000,000
Line of credit facility, expiration date prior to amendment				Aug. 13, 2015
Debt instrument maturity date				Aug. 14, 2017
Borrowing under the revolving line of credit facility				$ 10,800,000
Line of credit, available borrowing capacity				$ 4,200,000
SVB Agreement | 2013 Capital Growth Term Loan
Debt Instrument [Line Items]
Term loan		$ 15,000,000
Number of monthly installments for principal and interest payment | Installment		48
Interest rate on debt				4.00%
Outstanding balance of term loan				$ 4,000,000
Long-term debt				$ 300,000
Debt instrument, maturity, description				payable subsequent to December 31, 2017
SVB Agreement | 2013 Capital Growth Term Loan | Required Cash Balances Maintained With Silicon Valley Bank | Prime Rate
Debt Instrument [Line Items]
Percentage of margin	0.75%
SVB Agreement | 2013 Capital Growth Term Loan | Required Cash Balances Maintained With Silicon Valley Bank | LIBOR Rate
Debt Instrument [Line Items]
Percentage of margin	3.75%
SVB Agreement | 2013 Capital Growth Term Loan | Required Cash Balances Not Maintained With Silicon Valley Bank | Prime Rate
Debt Instrument [Line Items]
Percentage of margin	1.00%
SVB Agreement | 2013 Capital Growth Term Loan | Required Cash Balances Not Maintained With Silicon Valley Bank | LIBOR Rate
Debt Instrument [Line Items]
Percentage of margin	4.00%
Amended SVB Agreement | Required Cash Balances Maintained With Silicon Valley Bank | Prime Rate | Revolving Credit Facility
Debt Instrument [Line Items]
Percentage of margin			0.00%
Amended SVB Agreement | Required Cash Balances Maintained With Silicon Valley Bank | LIBOR Rate | Revolving Credit Facility
Debt Instrument [Line Items]
Percentage of margin			3.00%
Amended SVB Agreement | Required Cash Balances Not Maintained With Silicon Valley Bank | Prime Rate | Revolving Credit Facility
Debt Instrument [Line Items]
Percentage of margin			0.25%
Amended SVB Agreement | Required Cash Balances Not Maintained With Silicon Valley Bank | LIBOR Rate | Revolving Credit Facility
Debt Instrument [Line Items]
Percentage of margin			3.25%
Amended SVB Agreement | 2013 Capital Growth Term Loan | Required Cash Balances Maintained With Silicon Valley Bank | Prime Rate
Debt Instrument [Line Items]
Percentage of margin			0.25%
Amended SVB Agreement | 2013 Capital Growth Term Loan | Required Cash Balances Maintained With Silicon Valley Bank | LIBOR Rate
Debt Instrument [Line Items]
Percentage of margin			3.25%
Amended SVB Agreement | 2013 Capital Growth Term Loan | Required Cash Balances Not Maintained With Silicon Valley Bank | Prime Rate
Debt Instrument [Line Items]
Percentage of margin			0.50%
Amended SVB Agreement | 2013 Capital Growth Term Loan | Required Cash Balances Not Maintained With Silicon Valley Bank | LIBOR Rate
Debt Instrument [Line Items]
Percentage of margin			3.50%

Debt - Schedule of Future Debt

Debt - Schedule of Future Debt Principal Payments (Detail) $ in Thousands	Dec. 31, 2016USD ($)
Debt Disclosure [Abstract]
2,017	$ 14,528
2,018	312
Total future repayments of debt	$ 14,840

Commitments and Contingencies -

Commitments and Contingencies - Schedule of Future Minimum Lease Payments for Capital and Operating Leases (Detail) $ in Thousands	Dec. 31, 2016USD ($)
Capital leases
Capital leases due in 2017	$ 185
Total future minimum lease payments	185
Less: amount representing interest	(4)
Total capital lease obligation	181
Operating leases
Operating leases due in 2017	7,281
Operating leases due in 2018	7,164
Operating leases due in 2019	5,945
Operating leases due in 2020	3,451
Operating leases due in 2021	2,131
Total future minimum lease payments	$ 25,972

Commitments and Contingencies59

Commitments and Contingencies - Property and Equipment Recorded under Capital Leases (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Property Plant And Equipment [Abstract]
Property and equipment acquired under capital lease	$ 3,149	$ 3,149
Less: accumulated amortization	(2,600)	(2,212)
Property and equipment acquired under capital lease, net	$ 549	$ 937

Commitments and Contingencies60

Commitments and Contingencies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)Legal_Matter	Dec. 31, 2014USD ($)
Commitments And Contingencies Disclosure [Abstract]
Total rent expense	$ 4,500,000	$ 4,000,000	$ 2,200,000
Long-term sales tax liability	3,077,000	3,670,000
Current sales tax liability for non-contingent amounts	6,000,000	4,400,000
Accrued liabilities recorded for loss contingencies		$ 0
Number of ongoing legal matters | Legal_Matter		0
Contingent liabilities related to employment agreement	$ 0

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Stockholders Equity Note Disclosure [Line Items]
Common stock, voting rights	Holders of shares of Class A common stock and Class B common stock vote together as a single class on all matters (including the election of directors) except for specific circumstances that would adversely affect the powers, preferences, or rights of a particular class of common stock.
Common stock, conversion basis	each share of Class B common stock will convert automatically to Class A common stock upon: (i) the date specified by an affirmative vote or written consent of holders of at least 67% of the outstanding shares of Class B common stock, or (ii) the seven year anniversary of the closing date of the IPO (October 2, 2020)
Year of anniversary	7 years
Anniversary closing date of the IPO	Oct. 2, 2020
Early Exercises of Nonvested Options
Stockholders Equity Note Disclosure [Line Items]
Common stock outstanding related to the early exercise of non-vested options	0	2,330
Class A common stock
Stockholders Equity Note Disclosure [Line Items]
Common stock, par or stated value per share	$ 0.0001	$ 0.0001
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, voting rights	Holders of Class A common stock are entitled to one vote per share of Class A common stock
Class B common stock
Stockholders Equity Note Disclosure [Line Items]
Common stock, par or stated value per share	$ 0.0001	$ 0.0001
Common stock, shares authorized	250,000,000	250,000,000
Common stock, voting rights	holders of Class B common stock are entitled to 10 votes per share of Class B common stock.
Percentage of written consent of shareholders	67.00%
Undesignated Preferred Stock
Stockholders Equity Note Disclosure [Line Items]
Preferred stock, par value	$ 0.0001
Preferred stock, shares authorized	100,000,000	100,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Common Stock Reserved for Future Issuance (Detail)	Dec. 31, 2016shares
Class Of Stock [Line Items]
Common stock reserved for future issuance	135,024,000
2013 Equity incentive plan
Class Of Stock [Line Items]
Outstanding options and restricted stock unit awards	10,938,000
Available for future grants	8,702,558
2013 Employee stock purchase plan
Class Of Stock [Line Items]
Common stock reserved for future issuance	2,292,000
Available for future grants	2,291,580
Class B common stock
Class Of Stock [Line Items]
Common stock reserved for future issuance	13,091,000
Preferred Stock
Class Of Stock [Line Items]
Common stock reserved for future issuance	100,000,000

Share-Based Compensation - Summ

Share-Based Compensation - Summary of Share-Based Compensation Expense Recognized to Statements of Operations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 30,840	$ 22,088	$ 15,516
Cost of Revenues
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expense	3,165	2,054	1,294
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expense	7,296	5,387	3,343
Sales and Marketing
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expense	10,902	7,200	5,260
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 9,477	$ 7,447	$ 5,619

Share-Based Compensation - Su64

Share-Based Compensation - Summary of Share-Based Compensation Expense by Award Type (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	$ 30,840	$ 22,088	$ 15,516
Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	9,626	11,170	10,323
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	19,477	9,553	3,565
Employee Stock Purchase Plan Rights
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	$ 1,737	$ 1,365	$ 1,628

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Detail) - USD ($) $ in Millions	Jan. 29, 2014	Sep. 30, 2013	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance			135,024,000			135,024,000
Expected dividend yield						0.00%	0.00%	0.00%
2013 Employee stock purchase plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance			2,292,000			2,292,000
Available for future grants			2,291,580			2,291,580
Expected dividend yield						0.00%	0.00%	0.00%
Unrecognized share-based compensation expense, remaining weighted-average vesting periods						4 months 24 days	4 months 24 days
Eligible compensation under the Employee Stock Purchase Plan			15.00%			15.00%
Purchase of maximum shares by employees under Employee Stock Purchase Plan						3,000
Purchase price of Employee Stock Purchase Plan as a percentage of fair value						90.00%
Unrecognized share-based compensation expense			$ 0.7	$ 1.1		$ 0.7	$ 1.1
Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized share-based compensation expense			11	19.6		$ 11	$ 19.6
Unrecognized share-based compensation expense, remaining weighted-average vesting periods						2 years	2 years 6 months
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period contractual term						4 years
RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized share-based compensation expense, remaining weighted-average vesting periods						2 years 9 months 18 days	3 years
Unrecognized share-based compensation expense			$ 46.9	$ 35.2		$ 46.9	$ 35.2
Company's Historical Data
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Estimate expected weighting percentage			75.00%	50.00%	25.00%
Simplified Method Estimate
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Estimate expected weighting percentage			25.00%	50.00%	75.00%
Historical Volatilities of Peer Group
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Estimate expected weighting percentage					75.00%
Company's Historical Volatility
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Estimate expected weighting percentage			75.00%	50.00%
Company’s Peer Group Volatilities
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Estimate expected weighting percentage			25.00%	50.00%
Class A common stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, shares outstanding			61,292,000	58,480,000		61,292,000	58,480,000
Class A common stock | 2013 Employee stock purchase plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, shares outstanding			1,250,000			1,250,000
Percentage of outstanding shares of common stock						1.00%
Common stock shares, additional						719,624
Purchase price of Employee Stock Purchase Plan as a percentage of fair value						90.00%
2013 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of outstanding shares of common stock						5.00%
Available for future grants			8,702,558			8,702,558
Graded vesting schedule, number of years continuous service						4 years
Vesting period contractual term	7 years
2013 Equity Incentive Plan | Previously Reported
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period contractual term		10 years
2013 Equity Incentive Plan | Class A common stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance			6,200,000			6,200,000
Common stock, shares outstanding			6,200,000			6,200,000
Common stock shares, additional						3,598,122

Share-Based Compensation - Su66

Share-Based Compensation - Summary of Stock Option Activity Plans (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Number of Options Outstanding
Number of Options Outstanding, Beginning Balance	8,048	9,158	11,156
Number of Options Outstanding, Granted	547	1,881	1,302
Number of Options Outstanding, Exercised	(962)	(2,323)	(2,673)
Number of Options Outstanding, Canceled/Forfeited	(249)	(668)	(627)
Number of Options Outstanding, Ending Balance	7,384	8,048	9,158	11,156
Number of Options Outstanding, Vested and expected to vest	7,083
Number of Options Outstanding, Exercisable	5,359
Weighted-Average Exercise Price Per Share
Weighted-Average Exercise Price Per Share, Beginning Balance	$ 10.27	$ 8.23	$ 5.87
Weighted-Average Exercise Price Per Share, Granted	16.53	16.35	15.12
Weighted-Average Exercise Price Per Share, Exercised	10.01	6.82	1.97
Weighted-Average Exercise Price Per Share, Canceled/Forfeited	15.50	11.42	7.19
Weighted-Average Exercise Price Per Share, Ending Balance	10.59	$ 10.27	$ 8.23	$ 5.87
Weighted-Average Exercise Price Per Share, Vested and expected to vest	10.36
Weighted-Average Exercise Price Per Share, Exercisable	$ 8.68
Weighted-Average Contractual Term
Weighted-Average Contractual Term	5 years 3 months 18 days	6 years 2 months 12 days	7 years 2 months 12 days	7 years 8 months 12 days
Weighted-Average Contractual Term, Vested and expected to vest	5 years 3 months 18 days
Weighted-Average Contractual Term, Exercisable	5 years 1 month 6 days
Aggregate Intrinsic Value
Aggregate Intrinsic Value, Outstanding	$ 74,065	$ 107,091	$ 61,367	$ 139,484
Aggregate Intrinsic Value, Vested and expected to vest	72,684
Aggregate Intrinsic Value, Exercisable	$ 63,893

Share-Based Compensation - Sche

Share-Based Compensation - Schedule of Total Intrinsic Values of Options Exercised (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Total intrinsic value of options exercised	$ 10,718	$ 28,336	$ 41,454

Share-Based Compensation - Weig

Share-Based Compensation - Weighted Average Assumptions Used to Fair Value of Stock Options Granted (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility	47.00%	48.00%	48.00%
Risk-free interest rate	1.12%	1.22%	1.41%
Expected dividend yield	0.00%	0.00%	0.00%
Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	4 years 8 months 12 days	4 years 9 months 18 days	4 years 7 months 6 days
Grant date fair value of employee options	$ 6.72	$ 6.78	$ 6.16
Non Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	5 years 10 months 24 days	7 years 1 month 6 days	7 years

Share-Based Compensation - Su69

Share-Based Compensation - Summary of Assumptions Used to Value ESPP Rights Under the Black-Scholes Option-Pricing Model (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility	47.00%	48.00%	48.00%
Risk-free interest rate	1.12%	1.22%	1.41%
Expected dividend yield	0.00%	0.00%	0.00%
2013 Employee stock purchase plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 months	6 months	6 months
Expected volatility	41.00%	42.00%	50.00%
Risk-free interest rate	0.50%	0.25%	0.07%
Expected dividend yield	0.00%	0.00%	0.00%
Offering grant date fair value of ESPP rights	$ 5.29	$ 5.05	$ 3.93

Share-Based Compensation - Su70

Share-Based Compensation - Summary of RSUs Activity (Detail) - Restricted Stock Units - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of RSUs Outstanding, Beginning Balance	2,288	1,739	68
Number of RSUs Outstanding, Granted	2,798	1,365	1,915
Number of RSUs Outstanding, Released	(1,096)	(571)	(110)
Number of RSUs Outstanding, Canceled/Forfeited	(436)	(245)	(134)
Number of RSUs Outstanding, Ending Balance	3,554	2,288	1,739
Weighted-Average Grant Date Fair Value Per Share, Beginning Balance	$ 16.63	$ 14.87	$ 17.22
Weighted-Average Grant Date Fair Value Per Share, Granted	18.65	18.09	15.08
Weighted-Average Grant Date Fair Value Per Share, Released	16.77	15.45	16.82
Weighted-Average Grant Date Fair Value Per Share, Canceled/Forfeited	17.92	15.10	17.43
Weighted-Average Grant Date Fair Value Per Share, Ending Balance	$ 18.01	$ 16.63	$ 14.87
Aggregate Intrinsic Value, Outstanding	$ 73,261	$ 53,972	$ 25,617	$ 1,251

Income Taxes - Summary of Provi

Income Taxes - Summary of Provision (Benefit) for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current
State	$ 63	$ 71	$ 18
Foreign	209	85	114
Total current	272	156	132
Deferred
Federal		(1,312)
State		(99)
Foreign	(36)	(8)	(35)
Total deferred	(36)	(1,419)	(35)
Total income tax provision (benefit)	$ 236	$ (1,263)	$ 97

Income Taxes - Summary of Net L

Income Taxes - Summary of Net Loss Before Provision (Benefit) for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
United States	$ (27,908)	$ (28,870)	$ (50,065)
International	(1,165)	(4,492)	1,822
Loss before provision (benefit) for income taxes	$ (29,073)	$ (33,362)	$ (48,243)

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 31, 2014	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Line Items]
Statutory federal income tax rate		34.00%
Benefit for income taxes from release of valuation allowance			$ 1,411
Expected increase in equity if certain deferred tax assets are realized		$ 18,000
Net operating loss carry-forwards for federal income tax, expiration period		2,023
Net operating loss carry-forwards for state income tax, expiration period		2,013
Limitations in use of net operating losses		Events which may cause limitations in the amount of the net operating losses that the Company may use in any one year include, but are not limited to, a cumulative ownership change of more than 50% over a three-year period.
Period for cumulative ownership change		3 years
Valuation allowances, deferred tax asset, increase	$ 16,400	$ 7,800	11,100
Federal
Income Taxes [Line Items]
Net operating loss carry-forwards		$ 197,600	170,200
Research credit carry-forwards for tax purposes, expiration period		2,028
California
Income Taxes [Line Items]
Net operating loss carry-forwards		$ 137,600	117,000
Minimum
Income Taxes [Line Items]
Cumulative ownership change percentage		50.00%
Research credit carry-forward | Federal
Income Taxes [Line Items]
Research credit carry-forwards for tax purposes		$ 4,700	3,600
Research credit carry-forward | California
Income Taxes [Line Items]
Research credit carry-forwards for tax purposes		$ 5,200	$ 4,000

Income Taxes - Summary of Varia

Income Taxes - Summary of Variation of Effective Provision (Benefit) for Income Taxes from Statutory Federal Income Tax Rate (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Federal tax benefit at statutory rate	$ (9,885)	$ (11,343)	$ (16,403)
State tax, net of federal provision (benefit)	28	(34)	12
Research and development credits	(745)	(667)	(654)
Share-based compensation	960	1,086	1,836
Other permanent differences	600	325	211
Foreign tax rate differential	(225)	(80)	(33)
Net operating losses not recognized	9,503	10,762	15,128
Release of valuation allowance associated with acquisitions		(1,312)
Total income tax provision (benefit)	$ 236	$ (1,263)	$ 97

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Income Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Deferred tax assets
Net operating loss and credit carry-forwards	$ 59,863	$ 54,858	$ 45,552
Research and development credits	6,094	4,712	3,497
Sales tax liability	1,131	1,337	1,442
Share-based compensation	7,281	6,694	5,560
Accrued liabilities	6,525	6,090	4,676
Gross deferred tax assets	80,894	73,691	60,727
Valuation allowance	(79,319)	(71,514)	(60,405)
Total deferred tax assets	1,575	2,177	322
Deferred tax liabilities - Acquired intangibles	(803)	(1,164)
Deferred tax liabilities - Property and equipment	(606)	(883)	(197)
Net deferred tax assets	$ 166	$ 130	$ 125

Income Taxes - Summary of Recon

Income Taxes - Summary of Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation Of Unrecognized Tax Benefits Excluding Amounts Pertaining To Examined Tax Returns Roll Forward
Beginning balance	$ 1,897	$ 2,615	$ 933
Gross amount of increases in unrecognized tax benefits for tax positions taken in current year	538	499	465
Gross amount of increases in unrecognized tax benefits for tax positions taken in prior year	25		1,217
Gross amount of decreases in unrecognized tax benefits for tax positions taken in prior year		(1,217)
Ending balance	$ 2,460	$ 1,897	$ 2,615

Basic and Diluted Net Loss Pe77

Basic and Diluted Net Loss Per Share - Computation of Company's Basic and Diluted Net Loss Per Share of Common Stock (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Numerator
Net loss	$ (6,946)	$ (7,979)	$ (7,771)	$ (6,613)	$ (6,941)	$ (6,336)	$ (8,211)	$ (10,611)	$ (29,309)	$ (32,099)	$ (48,340)
Denominator
Weighted-average common shares for basic and diluted net loss per share									72,994	70,069	66,818
Basic and diluted net loss per share	$ (0.09)	$ (0.11)	$ (0.11)	$ (0.09)	$ (0.10)	$ (0.09)	$ (0.12)	$ (0.15)	$ (0.40)	$ (0.46)	$ (0.72)

Basic and Diluted Net Loss Pe78

Basic and Diluted Net Loss Per Share - Potential Shares of Common Stock Excluded from Diluted Weighted-Average Common Shares Outstanding (Detail) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential common shares excluded from diluted net loss per share	11,726	11,477	10,912
Repurchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential common shares excluded from diluted net loss per share		2	15
Equity Incentive Plans
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential common shares excluded from diluted net loss per share	11,726	11,475	10,897

Geographic Concentrations - Add

Geographic Concentrations - Additional Information (Detail) - Geographic Concentration Risk - Country	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Non-US | Sales Revenue, Segment
Concentration Risk [Line Items]
Number of foreign countries representing more than ten percent	0	0	0
Non-US | Long-lived Assets
Concentration Risk [Line Items]
Number of foreign countries representing more than ten percent	0	0
Minimum | U.S. | Sales Revenue, Segment
Concentration Risk [Line Items]
Concentration risk	90.00%	90.00%	90.00%
Minimum | U.S. | Long-lived Assets
Concentration Risk [Line Items]
Concentration risk	87.00%	86.00%

Selected Quarterly Financial 80

Selected Quarterly Financial Data (Unaudited) - Selected Unaudited Quarterly Consolidated Statements of Operations Data (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Consolidated Statements of Operations Data
Revenues	$ 104,503	$ 96,839	$ 91,844	$ 86,538	$ 83,439	$ 76,780	$ 70,691	$ 65,318	$ 379,724	$ 296,228	$ 219,887
Gross profit	79,851	73,384	69,480	64,798	60,577	54,447	49,162	44,771	287,513	208,957	143,114
Operating loss	(6,606)	(7,061)	(6,304)	(5,981)	(5,996)	(5,828)	(9,539)	(9,569)	(25,952)	(30,932)	(45,205)
Net loss	$ (6,946)	$ (7,979)	$ (7,771)	$ (6,613)	$ (6,941)	$ (6,336)	$ (8,211)	$ (10,611)	$ (29,309)	$ (32,099)	$ (48,340)
Basic and diluted net loss per share	$ (0.09)	$ (0.11)	$ (0.11)	$ (0.09)	$ (0.10)	$ (0.09)	$ (0.12)	$ (0.15)	$ (0.40)	$ (0.46)	$ (0.72)

Related-Party Transactions - Ad

Related-Party Transactions - Additional Information (Detail) - Alphabet Inc. - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Related Party Transaction [Line Items]
Total payables to related party	$ 1	$ 2
Total expenses incurred from related party	$ 14.2	$ 11.9	$ 10.1

Subsequent Event - Additional I

Subsequent Event - Additional Information (Detail) - USD ($) $ in Thousands	Feb. 10, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Subsequent Event [Line Items]
Term loan paid		$ 3,750	$ 6,142	$ 9,909
Subsequent Event | SVB Agreement | Revolving Credit Facility
Subsequent Event [Line Items]
Revolving line of credit paid	$ 10,800
Subsequent Event | SVB Agreement | 2013 Capital Growth Term Loan
Subsequent Event [Line Items]
Term loan paid	$ 3,400