0001595974-18-000110 | 10-Q | XBRL Viewer

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Document and Entity Information - shares	9 Months Ended
Document and Entity Information - shares	Sep. 30, 2018	Nov. 01, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	RUBICON PROJECT, INC.
Entity Central Index Key	0001595974
Document Type	10-Q
Document Period End Date	Sep. 30, 2018
Amendment Flag	false
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		50,751,765

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 82,354	$ 76,642
Marketable securities	14,486	52,504
Accounts receivable, net	155,328	165,890
Prepaid expenses and other current assets	8,781	9,620
TOTAL CURRENT ASSETS	260,949	304,656
Property and equipment, net	33,884	47,393
Internal use software development costs, net	14,432	12,734
Other assets, non-current	879	5,493
Intangible assets, net	10,971	13,359
TOTAL ASSETS	321,115	383,635
Current liabilities:
Accounts payable and accrued expenses	199,385	214,103
Other current liabilities	2,806	3,141
TOTAL CURRENT LIABILITIES	202,191	217,244
Other liabilities, non-current	1,172	1,780
TOTAL LIABILITIES	203,363	219,024
Commitments and contingencies (Note 10)
STOCKHOLDERS' EQUITY
Preferred stock, $0.00001 par value, 10,000 shares authorized at September 30, 2018 and December 31, 2017; 0 shares issued and outstanding at September 30, 2018 and December 31, 2017	0	0
Common stock, $0.00001 par value; 500,000 shares authorized at September 30, 2018 and December 31, 2017; 50,750 and 50,239 shares issued and outstanding at September 30, 2018 and December 31, 2017, respectively	1	0
Additional paid-in capital	431,294	418,354
Accumulated other comprehensive loss	(167)	41
Accumulated deficit	(313,376)	(253,784)
TOTAL STOCKHOLDERS' EQUITY	117,752	164,611
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 321,115	$ 383,635

Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, par or stated value per share (usd per share)	$ 0.00001	$ 0.00001
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par or stated value per share	$ 0.00001	$ 0.00001
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares, issued	50,751,000	50,239,000
Common stock, shares, outstanding	50,751,000	50,239,000

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Revenue	$ 29,729	$ 35,211	$ 83,253	$ 124,148
Expenses:
Cost of revenue	14,687	12,985	44,514	41,371
Sales and marketing	10,654	12,503	34,046	39,660
Technology and development	9,299	11,580	29,038	36,377
General and administrative	9,355	13,644	33,340	43,079
Restructuring and other exit costs	0	0	3,440	5,959
Impairment of goodwill	0	90,251	0	90,251
Total expenses	43,995	140,963	144,378	256,697
Loss from operations	(14,266)	(105,752)	(61,125)	(132,549)
Other (income) expense:
Interest income, net	(232)	(269)	(777)	(664)
Other income	(206)	(123)	(626)	(502)
Foreign exchange (gain) loss, net	(120)	242	(363)	1,093
Total other (income) expense, net	(558)	(150)	(1,766)	(73)
Loss before income taxes	(13,708)	(105,602)	(59,359)	(132,476)
Provision for income taxes	84	(2,031)	233	(1,510)
Net loss	$ (13,792)	$ (103,571)	$ (59,592)	$ (130,966)
Net loss per share:
Basic and Diluted (usd per share)	$ (0.27)	$ (2.11)	$ (1.19)	$ (2.69)
Weighted average shares used to compute net loss per share:
Basic and Diluted (in shares)	50,513	49,055	50,095	48,726

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net loss	$ (13,792)	$ (103,571)	$ (59,592)	$ (130,966)
Other comprehensive income (loss):
Unrealized gain on investments	9	3	15	3
Foreign currency translation adjustments	(99)	87	(223)	357
Other comprehensive income (loss)	(90)	90	(208)	360
Comprehensive loss	$ (13,882)	$ (103,481)	$ (59,800)	$ (130,606)

Consolidated Statements of Stockholders' Equity (Deficit) - 9 months ended Sep. 30, 2018 - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning Balance (in shares) at Dec. 31, 2017	50,239,000	50,239,000
Beginning Balance at Dec. 31, 2017	$ 164,611	$ 0	$ 418,354	$ 41	$ (253,784)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of common stock options (in shares)		50,000
Exercise of common stock options	45		45
Restricted stock awards, net (in shares)		(156,000)
Restricted stock awards, net	0	$ 0
Issuance of common stock related to employee stock purchase plan (in shares)		89,000
Issuance of common stock related to employee stock purchase plan	143		143
Issuance of common stock related to RSU vesting (in shares)		830,000
Issuance of common stock related to RSU vesting	1	$ 1
Shares withheld related to net share settlement (in shares)		(301,000)
Shares withheld related to net share settlement	(658)		(658)
Stock-based compensation	13,410		13,410
Other comprehensive loss	(208)			(208)
Net loss	$ (59,592)				(59,592)
Ending Balance (in shares) at Sep. 30, 2018	50,751,000	50,751,000
Ending Balance at Sep. 30, 2018	$ 117,752	$ 1	$ 431,294	$ (167)	$ (313,376)

Consolidated Statement of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
OPERATING ACTIVITIES:
Net loss	$ (59,592)	$ (130,966)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	26,355	27,154
Stock-based compensation	13,016	16,188
Impairment of goodwill	0	90,251
Loss on disposal of property and equipment	149	269
Provision for doubtful accounts	217	482
Accretion of available for sale securities	(374)	(163)
Unrealized foreign currency gains, net	(206)	372
Deferred income taxes	0	(1,453)
Changes in operating assets and liabilities, net of effect of business acquisitions:
Accounts receivable	10,318	58,876
Prepaid expenses and other assets	2,919	(1,315)
Accounts payable and accrued expenses	(14,415)	(49,972)
Other liabilities	(939)	(510)
Net cash provided by (used in) operating activities	(22,552)	9,213
INVESTING ACTIVITIES:
Purchases of property and equipment	(5,474)	(14,554)
Capitalized internal use software development costs	(6,569)	(6,127)
Payments to Acquire Businesses, Net of Cash Acquired	0	(38,610)
Investments in available-for-sale securities	(23,991)	(66,419)
Maturities of available-for-sale securities	55,650	67,650
Sales of available-for-sale securities	9,228	0
Net cash provided by (used in) investing activities	28,844	(58,060)
FINANCING ACTIVITIES:
Proceeds from exercise of stock options	45	391
Proceeds from issuance of common stock under employee stock purchase plan	143	444
Taxes paid related to net share settlement	(658)	(2,067)
Net cash used in financing activities	(470)	(1,232)
EFFECT OF EXCHANGE RATE CHANGES ON CASH, CASH EQUIVALENTS AND RESTRICTED CASH	(110)	186
CHANGE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	5,712	(49,893)
CASH, CASH EQUIVALENTS AND RESTRICTED CASH — Beginning of period	76,642	149,498
CASH, CASH EQUIVALENTS AND RESTRICTED CASH — End of period	82,354
SUPPLEMENTAL DISCLOSURES OF OTHER CASH FLOW INFORMATION:
Cash paid for income taxes	272	348
Cash paid for interest	46	46
Capitalized assets financed by accounts payable and accrued expenses	3	2,065
Capitalized stock-based compensation	$ 394	$ 338

Organization and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Organization and Summary of Significant Accounting Policies	Organization and Summary of Significant Accounting Policies Company Overview The Rubicon Project, Inc., or Rubicon Project (the "Company"), was formed on April 20, 2007 in Delaware and began operations in April 2007. The Company is headquartered in Los Angeles, California. The Company is a global advertising exchange that helps websites and applications thrive by giving them tools and expertise to sell ads easily and safely. In addition, the world’s leading agencies and brands rely on the Company's technology to execute tens of billions of advertising transactions each month. The Company provides a technology solution to automate the purchase and sale of digital advertising inventory for buyers and sellers. The Company's platform features applications and services for digital advertising sellers, including websites, mobile applications and other digital media properties, and their representatives, to sell their digital advertising inventory; applications and services for buyers, including advertisers, agencies, agency trading desks, demand side platforms, or DSPs, to buy digital advertising inventory; and a marketplace over which such transactions are executed. Together, these features power and enhance a comprehensive, transparent, independent advertising marketplace that brings buyers and sellers together and facilitates intelligent decision making and automated transaction execution for the digital advertising inventory managed on the Company's platform. The Company's clients include many of the world's leading publishers of websites and mobile applications and buyers of digital advertising inventory. Advertising inventory takes different forms, referred to as advertising units, is purchased and sold through different transactional methodologies, and allows advertising content to be presented to consumers through different channels. The Company's solution enables buyers and sellers to purchase and sell: • a comprehensive range of advertising units, including display, audio and video; • that are transacted through real-time bidding ("RTB"), which includes (i) direct sale of premium inventory, which the Company refers to as private marketplace ("PMP"), and (ii) open auction bidding, which the Company refers to as open marketplace ("OMP"); and • that are displayed across digital channels, including mobile web, mobile application, and desktop, as well as across various out-of-home channels, such as digital billboards. Risks and Uncertainties The Company has been negatively impacted by rapid changes in the ad tech industry, including demand by ad tech buyers for more efficiency and lower costs, changes in bidding technologies, and increased competition. In response to these challenges, the Company made significant reductions in fees charged to buyers during 2017 and in November 2017 eliminated its buyer fees altogether. The competitive pressures and reduced take rate resulted in lower revenue and cash flows in the first three quarters of 2018 compared to the prior year. In an effort to bring its costs into better alignment with reduced take rates, the Company undertook restructuring activities to reduce headcount and related operating costs, and also reduced its capital expenditures. Unless and until the Company is able to compensate for the fee reductions and reduced gross margins by continuing to increase advertising spend on its platform, or sufficiently reducing costs, it may not be able to grow its business and may continue to operate at a loss, depleting its cash resources and liquidity. If the Company continues to experience significant operating losses in the future, the Company may require additional liquidity to fund its operations. Basis of Presentation and Summary of Significant Accounting Policies The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with United States Generally Accepted Accounting Principles, or GAAP, for interim financial information and the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring adjustments) considered necessary for a fair statement of the results for the interim period presented have been included. Operating results for the nine months ended September 30, 2018 are not necessarily indicative of the results that may be expected for any future interim period, the year ending December 31, 2018, or for any future year. The condensed consolidated balance sheet at December 31, 2017 has been derived from the audited financial statements at that date, but does not include all of the disclosures required by GAAP. The accompanying condensed consolidated financial statements should be read in conjunction with the Company's audited consolidated financial statements and notes thereto for the year ended December 31, 2017 included in its 2017 Annual Report on Form 10-K. There have been no significant changes in the Company's accounting policies from those disclosed in its audited consolidated financial statements and notes thereto for the year ended December 31, 2017 included in its Annual Report on Form 10-K. Use of Estimates The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported and disclosed financial statements and accompanying footnotes. Actual results could differ materially from these estimates. Adoption of ASU 2018-07 The Company adopted ASU 2018-07—Stock Compensation (Topic 718) ("ASU 2018-07"), which expands the scope of Accounting Standards Codification Topic 718, Compensation—Stock Compensation to include share-based payments granted to non-employees in exchange for goods or services, as of July 1, 2018. As of the adoption date, the fair value of existing unvested awards held by non-employees was determined based on the adoption date fair value, which will be recognized over the remaining service period. Prospectively, the fair value of awards granted to non-employees will be determined as of the grant date and recognized over the service period, using the same treatment as awards granted to employees. In addition, for employees that transition into a non-employee contractor relationship with the Company subsequent to the adoption date, their existing awards will continue to be recognized at the original grant date fair value. There was no impact to the Company's consolidated financial statements resulting from the adoption of ASU 2018-07. Other Recently Adopted Accounting Pronouncements On January 1, 2018, the Company adopted the following accounting pronouncements, using a prospective adoption method, which did not have an impact on the Company's condensed consolidated financial statements and did not result in any significant policy changes: • Accounting Standards Update ("ASU") 2017-01—Business Combinations (Topic 805): Clarifying the Definition of a Business; and • ASU 2017-09—Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting. The Company has also adopted ASU 2016-15—Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments, although the retrospective adoption method did not have an impact on periods presented. The Company will apply this guidance to applicable future transactions. Recent Accounting Pronouncements Under the Jumpstart Our Business Startups Act, or the JOBS Act, the Company meets the definition of an emerging growth company. The Company has irrevocably elected to opt out of the extended transition period for complying with new or revised accounting standards pursuant to Section 107(b) of the JOBS Act. In February 2016, the Financial Accounting Standards Board ("FASB") issued ASU 2016-02—Leases (Topic 842) ("ASU 2016-02"), which requires an entity to recognize right-of-use assets and lease liabilities on its balance sheet and disclose key information about leasing arrangements. ASU 2016-02 offers specific accounting guidance for a lessee, a lessor, and sale and leaseback transactions. Lessees and lessors are required to disclose qualitative and quantitative information about leasing arrangements to enable a user of the financial statements to assess the amount, timing and uncertainty of cash flows arising from leases. Leases will be classified as either finance or operating, with classification affecting the pattern of expense recognition in the income statement. ASU 2016-02 is effective for annual reporting periods beginning after December 15, 2018, including interim periods within that reporting period, with early adoption permitted. ASU 2016-02 required a modified retrospective adoption approach, however subsequent guidance (discussed below) provides an additional option for adoption approach. The Company plans to adopt ASU 2016-02 as of January 1, 2019 using a prospective adoption method in accordance with ASU 2018-11—Leases (Topic 842): Targeted Improvements ("ASU 2018-11"). The Company is currently evaluating the effect this guidance will have on its consolidated financial statements and related disclosures, and anticipates the guidance to result in increases in its assets and liabilities as most of its operating lease commitments will be subject to the new standard and recognized as right-of-use assets and lease liabilities. In July 2018, the FASB issued ASU 2018-11, which updates some of the implementation requirements under Accounting Standards Codification Topic 842 on leases. ASU 2018-11 provides for an additional adoption approach that was not previously included in ASU 2016-02 that allows for a prospective application. This guidance eliminates the requirement to present prior year comparative lease disclosures once ASU 2016-02 is adopted, and must be adopted concurrently with ASU 2016-02. The Company plans to apply the adoption method made available by ASU 2018-11. In August 2018, the FASB issued ASU 2018-13—Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement ("ASU 2018-13"), to streamline the disclosure requirements of ASC Topic 820—Fair Value Measurement. ASU 2018 removes certain disclosure requirements, including the valuation process for Level 3 fair value measurements, and adds certain quantitative disclosures around Level 3 fair value measurements. This ASU is effective for annual reporting periods beginning after December 15, 2019, including interim periods within that reporting period, with early adoption permitted. The provisions of ASU 2018-13 are required to be adopted retrospectively, with the exception of disclosure of the range and weighted average of significant unobservable inputs used to develop Level 3 measurements, which can be adopted prospectively. The Company is currently evaluating the effect this guidance will have on its consolidated financial statements and related disclosures. In August 2018, the FASB issued ASU 2018-15—Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract ("ASU 2018-15"). ASU 2018-15 was issued to clarify the requirements of ASC 350-40—Intangibles—Goodwill and Other—Internal-Use Software ("ASC 350-40"). The ASU clarifies that implementation, setup and other upfront costs related to cloud hosting agreements should be accounted for under ASC 350-40. This ASU is effective for annual reporting periods beginning after December 15, 2019, including interim periods within that reporting period, with early adoption permitted. ASU 2018-15 can be applied either retrospectively or prospectively to all implementation costs incurred after the date of adoption. The Company is currently evaluating the effect this guidance will have on its consolidated financial statements.

Net Income (Loss) Per Share

9 Months Ended

Sep. 30, 2018

Earnings Per Share [Abstract]

Net Income (Loss) Per Share

The following table presents the basic and diluted net loss per share:


	Three Months Ended						Nine Months Ended
	September 30, 2018		September 30, 2017		September 30, 2018		September 30, 2017
	(in thousands, except per share data)
Basic and Diluted EPS:
Net loss	$	(13,792)	$	(103,571)	$	(59,592)	$	(130,966)
Weighted-average common shares outstanding	50,750		49,800		50,482		49,638
Weighted-average unvested restricted stock awards	(237)		(745)		(387)		(912)

Weighted-average common shares outstanding used to compute net loss per share	50,513		49,055		50,095		48,726
Basic and diluted net loss per share	$	(0.27)	$	(2.11)	$	(1.19)	$	(2.69)

The following weighted-average shares have been excluded from the calculation of diluted net loss per share attributable to common stockholders for each period presented because they are anti-dilutive:


	Three Months Ended			Nine Months Ended
	September 30, 2018	September 30, 2017	September 30, 2018	September 30, 2017
	(in thousands)			(in thousands)
Options to purchase common stock	162	187	72	154
Unvested restricted stock awards	208	130	232	240
Unvested restricted stock units	2,324	238	1,709	495
ESPP	94	44	64	49
Total shares excluded from net loss per share	2,788	599	2,077	938

Revenues

9 Months Ended

Sep. 30, 2018

Revenue from Contract with Customer [Abstract]

Revenues

Revenue

On January 1, 2018, the Company adopted Accounting Standards Update 2014-09—Revenue from Contracts with Customers (Topic 606) ("ASU 2014-09") using a modified retrospective approach applied to all contracts that generated revenue in the preceding year. The adoption of this guidance did not have an impact on the amount or timing of revenue recognized by the Company.

The Company generates revenue from transactions where it provides a platform for the purchase and sale of digital advertising inventory. The Company’s advertising automation solution is a marketplace for sellers of digital advertising inventory (providers of websites, mobile applications and other digital media properties, and their representatives) and buyers of digital advertising inventory (including advertisers, agencies, agency trading desks, and demand-side platforms). This solution incorporates proprietary machine-learning algorithms, sophisticated data processing, high-volume storage, detailed analytics capabilities, and a

distributed infrastructure. Together, these features form the basis for the Company’s automated advertising solution that brings buyers and sellers together and facilitates intelligent decision-making and automated transaction execution for the digital advertising inventory managed on the Company's platform. Digital advertising inventory is created when consumers access sellers’ content. Sellers provide digital advertising inventory to the Company’s platform in the form of advertising requests, or ad requests. When the Company receives ad requests from sellers, it sends bid requests to buyers, which enable buyers to bid on sellers’ digital advertising inventory. Winning bids can create advertising, or paid impressions, for the seller to present to the consumer.

The total volume of spending between buyers and sellers on the Company’s platform is referred to as advertising spend. The Company keeps a percentage of that advertising spend as a fee, and remits the remainder to the seller. The fee or “take rate” that the Company retains from the gross advertising spend on its platform is recognized as revenue. The fee earned on each transaction is based on the pre-existing agreement between the Company and the seller and the clearing price of the winning bid. The Company recognizes revenue upon fulfillment of its performance obligation to a customer, which occurs at the point in time an ad renders and is counted as a paid impression, subject to an underlying agreement existing with the customer and a fixed or determinable transaction price. Performance obligations for all transactions are satisfied, and the corresponding revenue is recognized, at a distinct point in time when an ad renders. The Company does not have arrangements with multiple performance obligations. The Company considers the following when determining if a contract exists under which the performance obligations have been satisfied: (i) contract approval by all parties, (ii) identification of each party’s rights regarding the goods or services to be transferred, (iii) specified payment terms, (iv) commercial substance of the contract, and (v) collectability of substantially all of the consideration is probable.

The Company has determined that it does not act as the principal in the purchase and sale of digital advertising inventory because it does not have control of the digital advertising inventory and does not set prices agreed upon within the auction marketplace, and therefore reports revenue on a net basis. In periods prior to the second quarter of 2017, the Company reported revenue on a gross basis for revenue associated with its intent marketing solution, as the Company determined that it acted as the principal in the purchase and sale of digital advertising inventory. The Company ceased offering its intent marketing solution after the first quarter of 2017, after which time, all of the Company’s revenues have been recorded on a net basis. Revenue generated by the Company’s intent marketing solution in 2017 prior to its cessation was $1.3 million, which is included in total revenue for the nine months ended September 30, 2017.

Payment terms are specified in agreements between the Company and the buyers and sellers on its exchange platform. The Company generally bills buyers at the end of each month for the full purchase price of impressions filled in that month. The Company recognizes volume discounts as a reduction of revenue as they are incurred. Specific payment terms may vary by agreement, but are generally seventy-five days or less. The Company's accounts receivable are recorded at the amount of gross billings to buyers, net of allowances for the amounts the company is responsible to collect. The Company's accounts payable related to amounts due to sellers are recorded at the net amount payable to sellers (see Note 5). Accordingly, both accounts receivable and accounts payable appear large in relation to revenue reported on a net basis.

The following table presents our revenue by channel for the three and nine months ended September 30, 2018 and 2017:


	Three Months Ended														Nine Months Ended
	September 30, 2018						September 30, 2017						September 30, 2018				September 30, 2017
	(in thousands, except percentages)
Channel:
Desktop	$	12,481	42	%	$	16,881	48	%	$	40,453	49	%	$	68,956	56	%
Mobile	17,248		58		18,330		52		42,800		51		55,192		44
Total	$	29,729	100	%	$	35,211	100	%	$	83,253	100	%	$	124,148	100	%

The following table presents our revenue disaggregated by geographic location, based on the location of the Company's sellers:


	Three Months Ended						Nine Months Ended
	September 30, 2018		September 30, 2017		September 30, 2018		September 30, 2017
	(in thousands)						(in thousands)
United States	$	19,731	$	22,689	$	54,201	$	78,350

International	9,998		12,522		29,052		45,798
Total	$	29,729	$	35,211	$	83,253	$	124,148

Fair Value Measurements

9 Months Ended

Sep. 30, 2018

Fair Value Disclosures [Abstract]

Fair Value Measurements

Recurring Fair Value Measurements

Fair value represents the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Observable inputs are based on market data obtained from independent sources. The fair value hierarchy is based on the following three levels of inputs, of which the first two are considered observable and the last one is considered unobservable:

• Level 1 – Quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date.

• Level 2 – Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly.

• Level 3 – Unobservable inputs.

The table below sets forth a summary of financial instruments that are measured at fair value on a recurring basis at September 30, 2018:


	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
	(in thousands)
Cash equivalents	$	19,078	$	19,078	$	—	$	—
Corporate debt securities	$	1,999	$	—	$	1,999	$	—
U.S. Treasury, government and agency debt securities	$	12,487	$	12,487	$	—	$	—

The table below sets forth a summary of financial instruments that are measured at fair value on a recurring basis at December 31, 2017:


	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
	(in thousands)
Cash equivalents	$	1,807	$	210	$	1,597	$	—
Corporate debt securities	$	25,098	$	—	$	25,098	$	—
U.S. Treasury, government and agency debt securities	$	29,901	$	29,901	$	—	$	—

At September 30, 2018 and December 31, 2017, cash equivalents of $19.1 million and $1.8 million, respectively, consisted of money market funds and commercial paper, with original maturities of three months or less. The carrying amounts of cash equivalents are classified as Level 1 or Level 2 depending on whether or not their fair values are based on quoted market prices for identical securities that are traded in an active market. The commercial paper included in cash equivalents at December 31, 2017 is classified as Level 2 since its fair value is not based on quoted market prices for identical securities that are traded in an active market, but rather is derived from similar securities. Corporate debt securities (which are included in marketable securities on the balance sheet) with fair values derived from similar securities rather than based on quoted market prices for identical securities, are classified as Level 2 as well. The fair values of the Company's U.S. treasury, government and agency debt securities are based on quoted market prices and classified as Level 1, and are included within marketable securities.

Non-Recurring Fair Value Measurements

Impairment of Goodwill

During the third quarter of 2017, the Company identified potential indications of impairment, which triggered a quantitative goodwill impairment assessment. The Company compared the fair value of its net assets, calculated using three valuation methodologies (one income approach and two market approaches), to the carrying value of the net assets. The fair value of the Company's net assets falls within Level 3 of the fair value hierarchy, as it was determined using unobservable inputs and relied on assumptions and estimates made by the Company's management. The valuation process is described below:

Income Approach. The Company first estimated the fair value of its net assets based on an income approach using the 2017 remaining year forecast, projections for growth from that base, and a terminal growth rate. The cash flows were discounted using the Company's estimated weighted average cost of capital rate of 16.2%. The value of net operating losses and the excess working capital were then added to the discounted cash flows to arrive at the income approach fair value of the Company's net assets.

Market Approach. The market approach used to determine the fair value of the Company's net assets was based upon a review of private and public company control transactions involving comparable companies. The Company performed two analyses under the market approach—a control premium analysis and a similar transaction analysis. In each of these analyses, the Company identified merger or acquisition transactions that were completed over the past three years involving targets that operate within the “Advertising” or “Internet Software and Services” industries and where the buyer was a strategic buyer. In the control premium analysis, the Company calculated a control premium paid in each of these transactions. After analyzing the comparable transactions, the Company applied a control premium of 15% to its adjusted public equity value to derive the fair value of its net assets. An additional method under the market approach, the similar transactions method, was utilized to determine the fair value of the Company's net assets under a strategic buyer purchase scenario. In this analysis, target companies were compared to the Company and multiples paid in transactions, specifically EBITDA, were analyzed and applied to the Company's adjusted EBITDA for the twelve months ended September 30, 2017. Based on the results of this analysis, an adjusted EBITDA multiple of 2.0x was applied to calculate the fair value of the Company's net assets. In determining the comparability of publicly-traded companies, several factors were analyzed, including products and solutions, markets, growth patterns, relative size, earnings trends and other financial characteristics.

The Company compared the fair value of its net assets using the three methodologies (one income approach and two market approaches) described above, to the carrying value and determined that its goodwill was fully impaired. The Company recorded an impairment of $90.3 million in the third quarter of 2017 to adjust its goodwill balance to its fair value of zero.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Other Balance Sheet Amounts

9 Months Ended

Sep. 30, 2018

Balance Sheet Related Disclosures [Abstract]

Other Balance Sheet Amounts

Investments in marketable securities as of September 30, 2018 consisted of the following:


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
	(in thousands)
Available-for-sale—short-term:
U.S. Treasury, government and agency debt securities	$	12,501	$	—	$	(14)	$	12,487
Corporate debt securities	1,999		—		—		1,999
Total	$	14,500	$	—	$	(14)	$	14,486

Investments in marketable securities as of December 31, 2017 consisted of the following:


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
	(in thousands)
Available-for-sale—short-term:
U.S. Treasury, government and agency debt securities	$	27,426	$	—	$	(20)	$	27,406
Corporate debt securities	25,098		—		—		25,098
Total	$	52,524	$	—	$	(20)	$	52,504
Available-for-sale—long-term:
U.S. Treasury, government and agency debt securities	$	2,504	$	—	$	(9)	$	2,495

The Company's available-for-sale securities had a weighted remaining contractual maturity of 0.2 years as of September 30, 2018. For the nine months ended September 30, 2018, the Company sold $9.2 million of available-for-sale investments, on which the realized gains were de minimis and there were no unrealized holding gains (losses) reclassified out of accumulated other comprehensive loss into the condensed consolidated statements of operations.

Accounts payable and accrued expenses included the following:


	September 30, 2018		December 31, 2017
	(in thousands)
Accounts payable—seller	$	188,659	$	203,694
Accounts payable—trade	5,081		3,764
Accrued employee-related payables	5,645		6,645
Total	$	199,385	$	214,103

As of December 31, 2016, the Company had $0.1 million of restricted cash, which is included in the beginning balance of cash, cash equivalents and restricted cash in the condensed consolidated statement of cash flows for the nine months ended September 30, 2017. Subsequent to that date, the Company has had no restricted cash.

Intangible Assets

9 Months Ended

Sep. 30, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill and Intangible Assets

The Company’s intangible assets as of September 30, 2018 and December 31, 2017 included the following:


	September 30, 2018		December 31, 2017
	(in thousands)
Amortizable intangible assets:
Developed technology	$	16,878	$	16,878

Non-compete agreements	690		690
Trademarks	20		20
Total identifiable intangible assets, gross	17,588		17,588
Accumulated amortization—intangible assets:
Developed technology	(6,182)		(4,062)

Non-compete agreements	(419)		(161)
Trademarks	(16)		(6)
Total accumulated amortization—intangible assets	(6,617)		(4,229)
Total identifiable intangible assets, net	$	10,971	$	13,359

Amortization of intangible assets for the three months ended September 30, 2018 and 2017 were $0.8 million and $1.2 million, respectively, and $2.4 million and $3.5 million for the nine months ended September 30, 2018 and 2017, respectively. The estimated remaining amortization expense associated with the Company's intangible assets was as follows as of September 30, 2018:


Fiscal Year	Amount
	(in thousands)
2018	$	797
2019	3,010
2020	2,826
2021	2,826
2022	1,512
Thereafter	—
Total	$	10,971

The Company recorded a goodwill impairment charge of $90.3 million during the third quarter of 2017, refer to Note 4 for additional details regarding the related valuation assessment process.

Business Combinations

9 Months Ended

Sep. 30, 2018

Business Combinations [Abstract]

Business Combinations

2017 Acquisition—nToggle, Inc.

On July 14, 2017, the Company completed the merger of nToggle, Inc. ("nToggle") with Caviar Acquisition Corp., a wholly owned subsidiary of the Company, with nToggle surviving as a wholly owned subsidiary of Rubicon Project. nToggle was a Boston, Massachusetts based programmatic advertising company with traffic-shaping technology. The primary reason for the acquisition

was to acquire technology, know-how and personnel that will enable the Company to offer services that make it easier and more cost-effective for buyers to find the inventory they seek among the billions of bid requests they receive. At closing, the Company paid net cash consideration of $38.6 million, which represents total purchase consideration of $40.6 million less acquired cash and cash equivalents of $2.0 million, to the stockholders, warrantholders, and holders of vested in-the-money options of nToggle. In addition, the Company assumed 432,482 outstanding unvested in-the-money options and 77,499 shares of restricted stock held by continuing employees, and issued an aggregate of 174,117 restricted stock units to the continuing employees under the Company's 2014 Inducement Grant Equity Incentive Plan. The financial results of nToggle have been included in our consolidated financial statements since the date of the acquisition.

The major classes of assets and liabilities to which the Company allocated the purchase price were as follows as of the acquisition date:


	Amount
	(in thousands)
Cash and cash equivalents	$	1,953
Accounts receivable	256
Prepaid and other assets	18
Fixed assets	763
Other non-current assets	82
Intangible assets	14,840
Goodwill	24,546
Total assets acquired	42,458
Accounts payable and accrued expenses	78
Deferred revenue	91
Deferred tax liability, net	1,719
Total liabilities assumed	1,888
Total net assets acquired	$	40,570

The Company recognized approximately $0.3 million of acquisition-related costs during the nine months ended September 30, 2017 that are included within general and administrative expenses in the Company’s condensed consolidated statements of operations. As part of the acquisition of nToggle, the Company acquired nToggle's net operating losses of approximately $9.3 million. In addition, the Company recorded deferred tax liabilities related to acquired intangibles of $5.5 million net of deferred tax assets of $3.8 million primarily related to net operating loss carryforwards.

The following table summarizes the components of the acquired intangible assets and estimated useful lives (in thousands, except for estimated useful life):


	September 30, 2017		Estimated Useful Life
Developed technology	$	14,130	5 years
Non-compete agreements	690		2 years
Trademark & trade name	20		1.5 years
Total intangible assets acquired	$	14,840

The intangible assets are amortized on a straight-line basis, which approximates the pattern in which the economic benefits are consumed, over their estimated useful lives. Amortization of developed technology is included in cost of revenues, the amortization related to non-compete agreements is included in technology and development, and amortization related to trademark and trade name is included in general and administrative.

Goodwill resulting from the acquisition was primarily attributable to acquired workforce, an increase in development capabilities, increased offerings to customers, and enhanced opportunities for growth and innovation. Refer to Note 4 for a description of the methods used to compute the charge for the impairment of consolidated goodwill of $90.3 million recorded in the third quarter of 2017. The acquired intangibles and goodwill resulting from the nToggle acquisition are not amortizable for tax purposes.

Unaudited Pro Forma Information - nToggle Acquisition

The following table provides unaudited condensed pro forma information to give effect to the nToggle acquisition as if it had occurred on January 1, 2017. The unaudited pro forma information reflects adjustments for additional amortization resulting from the fair value adjustments to assets acquired and liabilities assumed. The pro forma results do not include any anticipated cost

synergies or other effects of the integration of nToggle. Accordingly, pro forma amounts are not necessarily indicative of the results that actually would have occurred had the acquisition been completed on the date indicated, nor are they indicative of the actual or future operating results of the combined company.


	Three Months Ended		Nine Months Ended
	September 30, 2017		September 30, 2017
Pro forma revenues	$	35,270	$	125,083
Pro forma net loss	$	(103,895)	$	(134,665)

nToggle's technology was fully integrated into the Company's platform, and its pre-acquisition product is not offered on a stand-alone basis. As a result, the determination of nToggle's post-acquisition revenue and operating results on a stand-alone basis was impracticable.

Stock-Based Compensation

9 Months Ended

Sep. 30, 2018

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

Stock-Based Compensation

The Company’s equity incentive plans provide for the grant of equity awards, including non-statutory or incentive stock options, restricted stock awards ("RSAs"), and restricted stock units ("RSUs"), to the Company's employees, officers, directors, and consultants. The Company's board of directors administers the plans. Outstanding options vest based upon continued service at varying rates, but generally over four years from issuance with 25% vesting after one year of service and the remainder vesting monthly thereafter. RSAs and RSUs vest at varying rates, typically approximately 25% vesting after approximately one year of service and the remainder vesting semi-annually thereafter. The RSUs granted in the first nine months of 2018 included 2,800,000 RSUs that vest 50% on each of the first and second anniversaries of the grant date. Options, RSAs, and RSUs granted under the plans accelerate under certain circumstances for certain participants upon a change in control, as defined in the governing plan. An aggregate of 6,148,378 shares remained available for future grants at September 30, 2018 under the plans.

Stock Options

A summary of stock option activity for the nine months ended September 30, 2018 is as follows:


	Shares Under Option	Weighted- Average Exercise Price		Weighted- Average Contractual Life	Aggregate Intrinsic Value
	(in thousands)				(in thousands)
Outstanding at December 31, 2017	4,363	$	8.75
Granted	706	$	2.09
Exercised	(50)	$	0.91
Expired	(1,239)	$	10.15
Forfeited	(49)	$	4.54
Outstanding at September 30, 2018	3,731	$	7.18	7.0 years	$	1,469
Exercisable at September 30, 2018	2,198	$	9.49	5.8 years	$	467

The total intrinsic values of options exercised during the nine months ended September 30, 2018 was $0.1 million. At September 30, 2018, the Company had unrecognized employee stock-based compensation expense relating to nonvested stock options of approximately $3.8 million, which is expected to be recognized over a weighted-average period of 2.5 years. The weighted-average grant date fair value per share of stock options granted during the nine months ended September 30, 2018 was $1.10. Total fair value of options vested during the nine months ended September 30, 2018 was $2.7 million.

The Company estimates the fair value of stock options that contain service and/or performance conditions using the Black-Scholes option pricing model. The weighted-average input assumptions used by the Company were as follows:


	Three Months Ended						Nine Months Ended
	September 30, 2018		September 30, 2017		September 30, 2018		September 30, 2017
Expected term (in years)	5.4		5.3		5.7		5.8
Risk-free interest rate	2.75	%	1.88	%	2.53	%	2.03	%
Expected volatility	55	%	62	%	57	%	57	%
Dividend yield	—	%	—	%	—	%	—	%

Restricted Stock Awards

A summary of RSA activity for the nine months ended September 30, 2018 is as follows:


	Number of Shares	Weighted-Average Grant Date Fair Value
	(in thousands)
Nonvested shares of restricted stock awards outstanding at December 31, 2017	558	$	12.60
Granted	—	$	—
Canceled	(156)	$	13.82
Vested	(176)	$	11.81
Nonvested shares of restricted stock awards outstanding at September 30, 2018	226	$	12.37

The aggregate fair value of RSAs with service conditions that vested during the nine months ended September 30, 2018 was $0.5 million. At September 30, 2018, the Company had unrecognized stock-based compensation expense for RSAs with service conditions of $1.1 million, which is expected to be recognized over a weighted-average period of 1.2 years.

Restricted Stock Units

A summary of RSU activity for the nine months ended September 30, 2018 is as follows:


	Number of Shares	Weighted-Average Grant Date Fair Value
	(in thousands)
Nonvested restricted stock units outstanding at December 31, 2017	3,609	$	7.55
Granted	4,904	$	2.27
Canceled	(948)	$	5.27
Vested	(830)	$	8.02
Nonvested restricted stock units outstanding at September 30, 2018	6,735	$	3.97

The weighted-average grant date fair value per share of RSUs granted during the nine months ended September 30, 2018 was $2.27. The aggregate fair value of RSUs that vested during nine months ended September 30, 2018 was $1.8 million. At September 30, 2018, the intrinsic value of nonvested RSUs was $24.2 million. At September 30, 2018, the Company had unrecognized stock-based compensation expense relating to nonvested RSUs of approximately $20.1 million, which is expected to be recognized over a weighted-average period of 2.3 years.

Employee Stock Purchase Plan

In November 2013, the Company adopted the Company's 2014 Employee Stock Purchase Plan ("ESPP"). The ESPP is designed to enable eligible employees to periodically purchase shares of the Company's common stock at a discount through payroll deductions of up to 10% of their eligible compensation, subject to any plan limitations. At the end of each six-month offering period, employees are able to purchase shares at a price per share equal to 85% of the lower of the fair market value of the Company's common stock on the first trading day of the offering period or on the last trading day of the offering period. Offering periods generally commence and end in May and November of each year.

As of September 30, 2018, the Company has reserved 1,692,373 shares of its common stock for issuance under the ESPP.

Stock-Based Compensation Expense

Total stock-based compensation expense recorded in the condensed consolidated statements of operations was as follows:


	Three Months Ended						Nine Months Ended
	September 30, 2018		September 30, 2017		September 30, 2018		September 30, 2017
	(in thousands)						(in thousands)
Cost of revenue	$	72	$	115	$	256	$	295
Sales and marketing	1,187		1,115		3,530		3,524
Technology and development	691		1,122		2,163		3,178
General and administrative	1,910		2,294		6,669		7,631
Restructuring and other exit costs	—		—		398		1,560
Total stock-based compensation expense	$	3,860	$	4,646	$	13,016	$	16,188

Restructuring and Other Exit Costs

9 Months Ended

Sep. 30, 2018

Restructuring and Related Activities [Abstract]

Restructuring and Other Exit Costs

As part of its on-going efforts to control costs and create efficiencies, the Company underwent restructuring events throughout 2017 and in the first quarter of 2018. The objective of these restructuring activities was to streamline operations, prioritize resources for growth initiatives and increase profitability.

In January 2017, the Company announced that it would cease providing intent marketing services and would close its Toronto, Canada office as a result. For the nine months ended September 30, 2017, the Company recognized expenses of $6.0 million as restructuring and other exit costs related to the cessation of our intent marketing solution, including the closure of the Toronto office, as well as the realignment of the management team to a more cost efficient structure (collectively, the "2017 Restructuring Events"). A majority of the costs incurred in the nine months ended September 30, 2017 were severance and one-time termination benefit costs, of which $1.6 million related to non-cash stock-based compensation, the remainder of which related to facility closure costs. There were no restructuring and other exit costs incurred during the three months ended September 30, 2017.

In the first quarter of 2018, the Company announced its restructuring plan to reduce headcount to bring the Company's general and administrative operations into better alignment with the current size of the business and de-layer certain functions, and to reduce its investment in unprofitable projects (the "2018 Restructuring Events"). During the nine months ended September 30, 2018, the Company incurred restructuring and other exit costs of $3.4 million for severance and one-time termination benefits. There were no restructuring and other exit costs incurred during the three months ended September 30, 2018.

The following table summarizes restructuring and other exit cost activity for the 2018 Restructuring Events (in thousands):


Accrued restructuring and other exit costs at December 31, 2017	$	—
Restructuring and other exit costs	3,440
Cash paid for restructuring and other exit costs	(2,884)
Non-cash stock-based compensation for restructuring and other exit costs	(398)
Accrued restructuring and other exit costs at September 30, 2018	$	158

Accrued restructuring costs related to the 2017 Restructuring Events were $0.1 million at December 31, 2017 and were paid in the first half of 2018. Accrued restructuring costs are included within other liabilities on the Company's condensed consolidated balance sheets.

Income Taxes	9 Months Ended
Income Taxes	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes In determining quarterly provisions for income taxes, the Company uses the annual estimated effective tax rate applied to the actual year-to-date income. The Company's annual estimated effective tax rate differs from the statutory rate primarily as a result of state taxes, foreign taxes, nondeductible stock option expenses, and changes in the Company's valuation allowance. The Company recorded income tax expenses of $0.1 million and $0.2 million for the three and nine months ended September 30, 2018, respectively, and recorded income tax benefits of $2.0 million and $1.5 million for the three and nine months ended September 30, 2017, respectively. The tax provision for the three and nine months ended September 30, 2018 is primarily the result of the domestic valuation allowance and the tax liability associated with the foreign subsidiaries. On December 22, 2017, the U.S. government enacted the Tax Cuts and Jobs Act (the “Tax Act”). The Tax Act includes significant changes to the U.S. corporate income tax system including the following: a federal corporate rate reduction from 34% to 21%; limitations on the deductibility of executive compensation and research and development (“R&D”) expenditures; immediate expensing of qualified property; the creation of new minimum taxes such as the base erosion anti-abuse tax (“BEAT”) and Global Intangible Low Taxed Income (“GILTI”) tax; and the transition of U.S. international taxation from a worldwide tax system to a modified territorial tax system, which will result in a one time U.S. tax liability on those earnings which have not previously been repatriated to the U.S. (the “Transition Tax”). The Tax Act imposes a Transition Tax on previously untaxed accumulated and current earnings and profits (“E&P”) of certain of our foreign subsidiaries. To determine the amount of the Transition Tax, the Company determined, among other things, the amount of post-1986 E&P of the relevant subsidiaries. The Company recorded a provisional Transition Tax of $0.6 million, which reduced its U.S. net deferred tax assets for the year ended December 31, 2017. For the nine months ended September 30, 2018, there was no change to the provisional Transaction Tax recorded in the prior period. The SEC staff issued Staff Accounting Bulletin No. 118 (“SAB 118”) to address the application of U.S. GAAP in situations when a registrant does not have the necessary information available, prepared or analyzed in reasonable detail to complete the accounting for certain income tax effects of the Tax Act and allows the registrant to record provisional amounts during a measurement period not to extend beyond one year of the enactment date. The Company has recognized the actual impact of the revaluation of deferred tax balances and the provisional impact related to the one-time Transition Tax. The Company included these amounts in its consolidated financial statements for the year ended December 31, 2017. The ultimate impact may materially differ from these provisional amounts, due to, among other things, additional analysis, changes in interpretations and assumptions that have been made, additional regulatory guidance that may be issued, and actions that may be taken as a result of the Tax Act. The Company expects to complete its analysis within the measurement period in accordance with SAB 118. In addition, it is unclear how many U.S. states will incorporate the federal law changes, or portions thereof, into their tax codes and foreign governments may enact tax laws in response to the Tax Act that could result in further changes to global taxation and materially affect the Company's financial position and results of operations. Finally, the Tax Act imposes a new BEAT, essentially a 10% minimum tax (5% for tax years beginning after December 31, 2017, increasing to 10% for years beginning after December 31, 2018) calculated on a base equal to taxpayer’s income determined without tax benefits arising from base erosion payments. BEAT does not apply to corporations whose annual gross receipts for the three-taxable-year period ending with the preceding taxable year are less than $500 million. BEAT does not apply to the Company for the year ending December 31, 2018. Also, the Tax Act requires certain GILTI income earned by controlled foreign corporations (“CFCs”) to be included in the gross income of the CFCs’ U.S. shareholder (for tax years beginning after December 31, 2017). For the nine months ended September 30, 2018, the Company has included a provisional GILTI inclusion of $1.2 million for purposes of Accounting Standards Codification Topic 740. GAAP allows the Company to either (i) treat taxes due on future U.S. inclusions in taxable income related to BEAT and GILTI as current-period expense when incurred (the “period cost method”); or (ii) factor such amounts into the measurement of deferred taxes (the “deferred method”). The Company elected the period cost method. Due to uncertainty as to the realization of benefits from the Company's domestic and certain international deferred tax assets, including net operating loss carryforwards and research and development tax credits, the Company has a full valuation allowance reserved against such assets. The Company intends to continue to maintain a full valuation allowance on the deferred tax assets until there is sufficient evidence to support the reversal of all or some portion of these allowances. There were no material changes to the Company's unrecognized tax benefits in the nine months ended September 30, 2018, and the Company does not expect to have any significant changes to unrecognized tax benefits through the end of the fiscal year. Because of the Company's history of tax losses, all years remain open to tax audit. During the first quarter of 2017, the Internal Revenue Service commenced an examination of the 2015 tax year. During the second quarter of 2018, the Company received a Letter 590 from the IRS indicating that they had completed the examination and found no income tax related adjustments.

Commitments and Contingencies	9 Months Ended
Commitments and Contingencies	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Operating Leases The Company has commitments under non-cancelable operating leases for facilities, certain equipment, and its managed data center facilities. Total rental expenses were $3.2 million and $3.1 million for the three months ended September 30, 2018 and 2017, respectively, and $9.7 million and $9.4 million for the nine months ended September 30, 2018 and 2017, respectively. Additionally, expenses for cloud-based services related to data centers were $1.6 million and $0.8 million for the three months ended September 30, 2018 and 2017, respectively, and $5.0 million and $3.6 million for the nine months ended September 30, 2018 and 2017, respectively. As of September 30, 2018, expected future commitments related to operating leases were $16.8 million. As of September 30, 2018 and December 31, 2017, the Company had $2.9 million of letters of credit associated with office leases available for borrowing, on which there were no outstanding borrowings as of either date. Guarantees and Indemnification The Company’s agreements with sellers, buyers, and other third parties typically obligate it to provide indemnity and defense for losses resulting from claims of intellectual property infringement, damages to property or persons, business losses, or other liabilities. Generally, these indemnity and defense obligations relate to the Company’s own business operations, obligations, and acts or omissions. However, under some circumstances, the Company agrees to indemnify and defend contract counterparties against losses resulting from their own business operations, obligations, and acts or omissions, or the business operations, obligations, and acts or omissions of third parties. For example, because the Company’s business interposes the Company between buyers and sellers in various ways, buyers often require the Company to indemnify them against acts and omissions of sellers, and sellers often require the Company to indemnify them against acts and omissions of buyers. In addition, the Company’s agreements with sellers, buyers, and other third parties typically include provisions limiting the Company’s liability to the counterparty, and the counterparty’s liability to the Company. These limits sometimes do not apply to certain liabilities, including indemnity obligations. These indemnity and limitation of liability provisions generally survive termination or expiration of the agreements in which they appear. The Company has also entered into indemnification agreements with its directors, executive officers and certain other officers that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors, officers or employees. No material demands have been made upon the Company to provide indemnification under such agreements and there are no claims that the Company is aware of that could have a material effect on the Company’s condensed consolidated financial statements. Litigation The Company and its subsidiaries may from time to time be parties to legal or regulatory proceedings, lawsuits and other claims incident to their business activities and to the Company’s status as a public company. Such matters may include, among other things, assertions of contract breach or intellectual property infringement, claims for indemnity arising in the course of the Company’s business, regulatory investigations or enforcement proceedings, and claims by persons whose employment has been terminated. Such matters are subject to many uncertainties, and outcomes are not predictable with assurance. Consequently, management is unable to ascertain the ultimate aggregate amount of monetary liability, amounts which may be covered by insurance or recoverable from third parties, or the financial impact with respect to such matters as of September 30, 2018. However, based on management’s knowledge as of September 30, 2018, management believes that the final resolution of these matters known at such date, individually and in the aggregate, will not have a material adverse effect upon the Company’s condensed consolidated financial position, results of operations or cash flows. On March 31, 2017, Guardian News & Media Limited ("Guardian") issued proceedings (the "Complaint") against the Company in the Chancery Division of the High Court of Justice in England & Wales. The Complaint alleged that the Company underpaid Guardian for digital advertising inventory sold by Guardian through the Company's platform as a result of the fact that the Company charged fees to buyers of that inventory. Guardian claimed the Company was precluded from charging buyer fees as a result of the contractual arrangements with Guardian and English agency law principles, as well as representations it allegedly made to Guardian. The Complaint claimed damages including loss of revenue, interest, and costs. On October 11, 2018, the Company and Guardian mutually agreed to resolve their dispute and the High Court proceedings have been discontinued. Though the terms of the settlement agreement are confidential, the settlement is immaterial to the Company from a financial standpoint. Employment Contracts The Company has entered into severance agreements with certain employees and officers. The Company may be required to pay severance and accelerate the vesting of certain equity awards in the event of involuntary terminations.

Debt	9 Months Ended
Debt	Sep. 30, 2018
Debt Disclosure [Abstract]
Debt	Debt On September 26, 2018, the Company amended and restated its loan and security agreement with Silicon Valley Bank (the "Loan Agreement"), which was scheduled to expire on September 27, 2018. The Loan Agreement provides a senior secured revolving credit facility of up to $40.0 million with a maturity date of September 26, 2020. The amount available for borrowing as of September 30, 2018 is $30.0 million due to a $10.0 million reserve that will be released if the Company maintains positive Adjusted EBITDA for any trailing twelve-month period. The Company incurred $0.1 million of debt issuance fees that were capitalized and are being amortized over the term of the Loan Agreement. An unused revolver fee in the amount of 0.15% per annum of the average unused portion of the revolver line is charged and is payable monthly in arrears. The Company may elect for advances to bear interest calculated by reference to prime or LIBOR. If the Company elects LIBOR, amounts outstanding under the amended credit facility bear interest at a rate per annum equal to LIBOR plus 2.50% if a streamline period applies or LIBOR plus 4.00% if a streamline period does not apply. If the Company elects prime, advances bear interest at a rate of prime plus 0.50% if a streamline period applies or prime plus 2.00% if a streamline period does not apply. A streamline period is any period during which an event of default does not exist and the Company's Adjusted Quick Ratio (as defined in the Loan Agreement) is at least 1.05 for each day in the preceding month. The Loan Agreement is collateralized by security interests in substantially all of the Company's assets. Subject to certain exceptions, the Loan Agreement restricts the Company's ability to, among other things, pay dividends, sell assets, make changes to the nature of the business, engage in mergers or acquisitions, incur, assume or permit to exist, additional indebtedness and guarantees, create or permit to exist, liens, make distributions or redeem or repurchase capital stock, or make other investments, engage in transactions with affiliates, make payments with respect to subordinated debt, and enter into certain transactions without the consent of the financial institution. If a streamline period is not in effect, the Company is required to maintain a lockbox arrangement where customer payments received in the lockbox will immediately reduce the amounts outstanding on the credit facility. The Loan Agreement requires the Company to comply with financial covenants, including a minimum Adjusted Quick Ratio and the achievement of certain Adjusted EBITDA targets. On a monthly basis, or quarterly if there were no advances outstanding during the calendar quarter, the Company is required to maintain a minimum Adjusted Quick Ratio of: (i) 1.00 if the trailing six month adjusted EBITDA is $0 or less, or (ii) 0.90 if the trailing six month adjusted EBITDA is greater than $0. If the Company’s Adjusted Quick Ratio is 1.05 or greater, a streamline period applies. As of September 30, 2018, the Company's Adjusted Quick Ratio was 1.2, which is in compliance with its covenant requirement and is higher than the minimum Adjusted Quick Ratio required to qualify for a streamline period. The Company must also maintain the following trailing twelve month Adjusted EBITDA targets as of the end of each quarter as follows: (1) September 30, 2018 through June 30, 2019 Adjusted EBITDA must be within 20% of the Adjusted EBITDA projections that were delivered to Silicon Valley Bank; (2) September 30, 2019 Adjusted EBITDA of $1 or greater; and (3) December 31, 2019 and thereafter, Adjusted EBITDA of $5.0 million or greater. As of September 30, 2018, the Company was in compliance with the Adjusted EBITDA covenant. The Loan Agreement also includes customary representations and warranties, affirmative covenants, and events of default, including events of default upon a change of control and material adverse change (as defined in the Loan Agreement). Following an event of default, SVB would be entitled to, among other things, accelerate payment of amounts due under the credit facility and exercise all rights of a secured creditor. As of September 30, 2018, there were no amounts outstanding under the Loan Agreement. Future availability under the credit facility is dependent on several factors including the available borrowing base and compliance with future covenant requirements.

Organization and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	Basis of Presentation and Summary of Significant Accounting Policies The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with United States Generally Accepted Accounting Principles, or GAAP, for interim financial information and the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring adjustments) considered necessary for a fair statement of the results for the interim period presented have been included. Operating results for the nine months ended September 30, 2018 are not necessarily indicative of the results that may be expected for any future interim period, the year ending December 31, 2018, or for any future year. The condensed consolidated balance sheet at December 31, 2017 has been derived from the audited financial statements at that date, but does not include all of the disclosures required by GAAP. The accompanying condensed consolidated financial statements should be read in conjunction with the Company's audited consolidated financial statements and notes thereto for the year ended December 31, 2017 included in its 2017 Annual Report on Form 10-K. There have been no significant changes in the Company's accounting policies from those disclosed in its audited consolidated financial statements and notes thereto for the year ended December 31, 2017 included in its Annual Report on Form 10-K.
Use of Estimates	Use of Estimates The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported and disclosed financial statements and accompanying footnotes. Actual results could differ materially from these estimates.
Recent Accounting Pronouncements	Adoption of ASU 2018-07 The Company adopted ASU 2018-07—Stock Compensation (Topic 718) ("ASU 2018-07"), which expands the scope of Accounting Standards Codification Topic 718, Compensation—Stock Compensation to include share-based payments granted to non-employees in exchange for goods or services, as of July 1, 2018. As of the adoption date, the fair value of existing unvested awards held by non-employees was determined based on the adoption date fair value, which will be recognized over the remaining service period. Prospectively, the fair value of awards granted to non-employees will be determined as of the grant date and recognized over the service period, using the same treatment as awards granted to employees. In addition, for employees that transition into a non-employee contractor relationship with the Company subsequent to the adoption date, their existing awards will continue to be recognized at the original grant date fair value. There was no impact to the Company's consolidated financial statements resulting from the adoption of ASU 2018-07. Other Recently Adopted Accounting Pronouncements On January 1, 2018, the Company adopted the following accounting pronouncements, using a prospective adoption method, which did not have an impact on the Company's condensed consolidated financial statements and did not result in any significant policy changes: • Accounting Standards Update ("ASU") 2017-01—Business Combinations (Topic 805): Clarifying the Definition of a Business; and • ASU 2017-09—Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting. The Company has also adopted ASU 2016-15—Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments, although the retrospective adoption method did not have an impact on periods presented. The Company will apply this guidance to applicable future transactions. Recent Accounting Pronouncements Under the Jumpstart Our Business Startups Act, or the JOBS Act, the Company meets the definition of an emerging growth company. The Company has irrevocably elected to opt out of the extended transition period for complying with new or revised accounting standards pursuant to Section 107(b) of the JOBS Act. In February 2016, the Financial Accounting Standards Board ("FASB") issued ASU 2016-02—Leases (Topic 842) ("ASU 2016-02"), which requires an entity to recognize right-of-use assets and lease liabilities on its balance sheet and disclose key information about leasing arrangements. ASU 2016-02 offers specific accounting guidance for a lessee, a lessor, and sale and leaseback transactions. Lessees and lessors are required to disclose qualitative and quantitative information about leasing arrangements to enable a user of the financial statements to assess the amount, timing and uncertainty of cash flows arising from leases. Leases will be classified as either finance or operating, with classification affecting the pattern of expense recognition in the income statement. ASU 2016-02 is effective for annual reporting periods beginning after December 15, 2018, including interim periods within that reporting period, with early adoption permitted. ASU 2016-02 required a modified retrospective adoption approach, however subsequent guidance (discussed below) provides an additional option for adoption approach. The Company plans to adopt ASU 2016-02 as of January 1, 2019 using a prospective adoption method in accordance with ASU 2018-11—Leases (Topic 842): Targeted Improvements ("ASU 2018-11"). The Company is currently evaluating the effect this guidance will have on its consolidated financial statements and related disclosures, and anticipates the guidance to result in increases in its assets and liabilities as most of its operating lease commitments will be subject to the new standard and recognized as right-of-use assets and lease liabilities. In July 2018, the FASB issued ASU 2018-11, which updates some of the implementation requirements under Accounting Standards Codification Topic 842 on leases. ASU 2018-11 provides for an additional adoption approach that was not previously included in ASU 2016-02 that allows for a prospective application. This guidance eliminates the requirement to present prior year comparative lease disclosures once ASU 2016-02 is adopted, and must be adopted concurrently with ASU 2016-02. The Company plans to apply the adoption method made available by ASU 2018-11. In August 2018, the FASB issued ASU 2018-13—Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement ("ASU 2018-13"), to streamline the disclosure requirements of ASC Topic 820—Fair Value Measurement. ASU 2018 removes certain disclosure requirements, including the valuation process for Level 3 fair value measurements, and adds certain quantitative disclosures around Level 3 fair value measurements. This ASU is effective for annual reporting periods beginning after December 15, 2019, including interim periods within that reporting period, with early adoption permitted. The provisions of ASU 2018-13 are required to be adopted retrospectively, with the exception of disclosure of the range and weighted average of significant unobservable inputs used to develop Level 3 measurements, which can be adopted prospectively. The Company is currently evaluating the effect this guidance will have on its consolidated financial statements and related disclosures. In August 2018, the FASB issued ASU 2018-15—Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract ("ASU 2018-15"). ASU 2018-15 was issued to clarify the requirements of ASC 350-40—Intangibles—Goodwill and Other—Internal-Use Software ("ASC 350-40"). The ASU clarifies that implementation, setup and other upfront costs related to cloud hosting agreements should be accounted for under ASC 350-40. This ASU is effective for annual reporting periods beginning after December 15, 2019, including interim periods within that reporting period, with early adoption permitted. ASU 2018-15 can be applied either retrospectively or prospectively to all implementation costs incurred after the date of adoption. The Company is currently evaluating the effect this guidance will have on its consolidated financial statements.

Net Income (Loss) Per Share (Tables)

9 Months Ended

Sep. 30, 2018

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted

The following table presents the basic and diluted net loss per share:


	Three Months Ended						Nine Months Ended
	September 30, 2018		September 30, 2017		September 30, 2018		September 30, 2017
	(in thousands, except per share data)
Basic and Diluted EPS:
Net loss	$	(13,792)	$	(103,571)	$	(59,592)	$	(130,966)
Weighted-average common shares outstanding	50,750		49,800		50,482		49,638
Weighted-average unvested restricted stock awards	(237)		(745)		(387)		(912)

Weighted-average common shares outstanding used to compute net loss per share	50,513		49,055		50,095		48,726
Basic and diluted net loss per share	$	(0.27)	$	(2.11)	$	(1.19)	$	(2.69)

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share


	Three Months Ended			Nine Months Ended
	September 30, 2018	September 30, 2017	September 30, 2018	September 30, 2017
	(in thousands)			(in thousands)
Options to purchase common stock	162	187	72	154
Unvested restricted stock awards	208	130	232	240
Unvested restricted stock units	2,324	238	1,709	495
ESPP	94	44	64	49
Total shares excluded from net loss per share	2,788	599	2,077	938

Revenues (Tables)

9 Months Ended

Sep. 30, 2018

Revenue from Contract with Customer [Abstract]

Disaggregation of Revenue

The following table presents our revenue by channel for the three and nine months ended September 30, 2018 and 2017:


	Three Months Ended														Nine Months Ended
	September 30, 2018						September 30, 2017						September 30, 2018				September 30, 2017
	(in thousands, except percentages)
Channel:
Desktop	$	12,481	42	%	$	16,881	48	%	$	40,453	49	%	$	68,956	56	%
Mobile	17,248		58		18,330		52		42,800		51		55,192		44
Total	$	29,729	100	%	$	35,211	100	%	$	83,253	100	%	$	124,148	100	%

The following table presents our revenue disaggregated by geographic location, based on the location of the Company's sellers:


	Three Months Ended						Nine Months Ended
	September 30, 2018		September 30, 2017		September 30, 2018		September 30, 2017
	(in thousands)						(in thousands)
United States	$	19,731	$	22,689	$	54,201	$	78,350

International	9,998		12,522		29,052		45,798
Total	$	29,729	$	35,211	$	83,253	$	124,148

Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2018

Fair Value Disclosures [Abstract]

Fair Value, Assets Measured on Recurring Basis

The table below sets forth a summary of financial instruments that are measured at fair value on a recurring basis at September 30, 2018:


	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
	(in thousands)
Cash equivalents	$	19,078	$	19,078	$	—	$	—
Corporate debt securities	$	1,999	$	—	$	1,999	$	—
U.S. Treasury, government and agency debt securities	$	12,487	$	12,487	$	—	$	—

The table below sets forth a summary of financial instruments that are measured at fair value on a recurring basis at December 31, 2017:


	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
	(in thousands)
Cash equivalents	$	1,807	$	210	$	1,597	$	—
Corporate debt securities	$	25,098	$	—	$	25,098	$	—
U.S. Treasury, government and agency debt securities	$	29,901	$	29,901	$	—	$	—

Other Balance Sheet Amounts (Tables)

9 Months Ended

Sep. 30, 2018

Balance Sheet Related Disclosures [Abstract]

Investments in Marketable Securities

Investments in marketable securities as of September 30, 2018 consisted of the following:


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
	(in thousands)
Available-for-sale—short-term:
U.S. Treasury, government and agency debt securities	$	12,501	$	—	$	(14)	$	12,487
Corporate debt securities	1,999		—		—		1,999
Total	$	14,500	$	—	$	(14)	$	14,486

Investments in marketable securities as of December 31, 2017 consisted of the following:


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
	(in thousands)
Available-for-sale—short-term:
U.S. Treasury, government and agency debt securities	$	27,426	$	—	$	(20)	$	27,406
Corporate debt securities	25,098		—		—		25,098
Total	$	52,524	$	—	$	(20)	$	52,504
Available-for-sale—long-term:
U.S. Treasury, government and agency debt securities	$	2,504	$	—	$	(9)	$	2,495

Schedule of Accounts Payable and Accrued Liabilities

Accounts payable and accrued expenses included the following:


	September 30, 2018		December 31, 2017
	(in thousands)
Accounts payable—seller	$	188,659	$	203,694
Accounts payable—trade	5,081		3,764
Accrued employee-related payables	5,645		6,645
Total	$	199,385	$	214,103

Intangible Assets (Tables)

9 Months Ended

Sep. 30, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Finite-Lived Intangible Assets

The Company’s intangible assets as of September 30, 2018 and December 31, 2017 included the following:


	September 30, 2018		December 31, 2017
	(in thousands)
Amortizable intangible assets:
Developed technology	$	16,878	$	16,878

Non-compete agreements	690		690
Trademarks	20		20
Total identifiable intangible assets, gross	17,588		17,588
Accumulated amortization—intangible assets:
Developed technology	(6,182)		(4,062)

Non-compete agreements	(419)		(161)
Trademarks	(16)		(6)
Total accumulated amortization—intangible assets	(6,617)		(4,229)
Total identifiable intangible assets, net	$	10,971	$	13,359

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense

The estimated remaining amortization expense associated with the Company's intangible assets was as follows as of September 30, 2018:


Fiscal Year	Amount
	(in thousands)
2018	$	797
2019	3,010
2020	2,826
2021	2,826
2022	1,512
Thereafter	—
Total	$	10,971

Business Combinations (Tables)

9 Months Ended

Sep. 30, 2018

Business Combinations [Abstract]

Schedule of Recognized Identified Assets Acquired and Liabilities Assumed

The major classes of assets and liabilities to which the Company allocated the purchase price were as follows as of the acquisition date:


	Amount
	(in thousands)
Cash and cash equivalents	$	1,953
Accounts receivable	256
Prepaid and other assets	18
Fixed assets	763
Other non-current assets	82
Intangible assets	14,840
Goodwill	24,546
Total assets acquired	42,458
Accounts payable and accrued expenses	78
Deferred revenue	91
Deferred tax liability, net	1,719
Total liabilities assumed	1,888
Total net assets acquired	$	40,570

Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination

The following table summarizes the components of the acquired intangible assets and estimated useful lives (in thousands, except for estimated useful life):


	September 30, 2017		Estimated Useful Life
Developed technology	$	14,130	5 years
Non-compete agreements	690		2 years
Trademark & trade name	20		1.5 years
Total intangible assets acquired	$	14,840

Business Acquisition, Pro Forma Information


	Three Months Ended		Nine Months Ended
	September 30, 2017		September 30, 2017
Pro forma revenues	$	35,270	$	125,083
Pro forma net loss	$	(103,895)	$	(134,665)

Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2018

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

Schedule of Share-based Compensation, Stock Options, Activity

A summary of stock option activity for the nine months ended September 30, 2018 is as follows:


	Shares Under Option	Weighted- Average Exercise Price		Weighted- Average Contractual Life	Aggregate Intrinsic Value
	(in thousands)				(in thousands)
Outstanding at December 31, 2017	4,363	$	8.75
Granted	706	$	2.09
Exercised	(50)	$	0.91
Expired	(1,239)	$	10.15
Forfeited	(49)	$	4.54
Outstanding at September 30, 2018	3,731	$	7.18	7.0 years	$	1,469
Exercisable at September 30, 2018	2,198	$	9.49	5.8 years	$	467

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions


	Three Months Ended						Nine Months Ended
	September 30, 2018		September 30, 2017		September 30, 2018		September 30, 2017
Expected term (in years)	5.4		5.3		5.7		5.8
Risk-free interest rate	2.75	%	1.88	%	2.53	%	2.03	%
Expected volatility	55	%	62	%	57	%	57	%
Dividend yield	—	%	—	%	—	%	—	%

Nonvested Restricted Stock Shares Activity

A summary of RSA activity for the nine months ended September 30, 2018 is as follows:


	Number of Shares	Weighted-Average Grant Date Fair Value
	(in thousands)
Nonvested shares of restricted stock awards outstanding at December 31, 2017	558	$	12.60
Granted	—	$	—
Canceled	(156)	$	13.82
Vested	(176)	$	11.81
Nonvested shares of restricted stock awards outstanding at September 30, 2018	226	$	12.37

Schedule of Nonvested Restricted Stock Units Activity

A summary of RSU activity for the nine months ended September 30, 2018 is as follows:


	Number of Shares	Weighted-Average Grant Date Fair Value
	(in thousands)
Nonvested restricted stock units outstanding at December 31, 2017	3,609	$	7.55
Granted	4,904	$	2.27
Canceled	(948)	$	5.27
Vested	(830)	$	8.02
Nonvested restricted stock units outstanding at September 30, 2018	6,735	$	3.97

Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs for all Plans

Total stock-based compensation expense recorded in the condensed consolidated statements of operations was as follows:


	Three Months Ended						Nine Months Ended
	September 30, 2018		September 30, 2017		September 30, 2018		September 30, 2017
	(in thousands)						(in thousands)
Cost of revenue	$	72	$	115	$	256	$	295
Sales and marketing	1,187		1,115		3,530		3,524
Technology and development	691		1,122		2,163		3,178
General and administrative	1,910		2,294		6,669		7,631
Restructuring and other exit costs	—		—		398		1,560
Total stock-based compensation expense	$	3,860	$	4,646	$	13,016	$	16,188

Restructuring and Other Exit Costs (Tables)

9 Months Ended

Sep. 30, 2018

Restructuring and Related Activities [Abstract]

Schedule of Restructuring and Other Exit Costs

The following table summarizes restructuring and other exit cost activity for the 2018 Restructuring Events (in thousands):


Accrued restructuring and other exit costs at December 31, 2017	$	—
Restructuring and other exit costs	3,440
Cash paid for restructuring and other exit costs	(2,884)
Non-cash stock-based compensation for restructuring and other exit costs	(398)
Accrued restructuring and other exit costs at September 30, 2018	$	158

Net Income (Loss) Per Share (Basic and Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Basic and Diluted EPS:
Net loss	$ (13,792)	$ (103,571)	$ (59,592)	$ (130,966)
Weighted-average common shares outstanding	50,750	49,800	50,482	49,638
Weighted-average unvested restricted shares	(237)	(745)	(387)	(912)
Weighted-average common shares outstanding used to compute net loss per share	50,513	49,055	50,095	48,726
Basic and diluted net loss per share	$ (0.27)	$ (2.11)	$ (1.19)	$ (2.69)

Net Income (Loss) Per Share (Shares Excluded and Included in Calculation of Diluted Earnings Per Share) (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded from net income (loss) per share (in shares)	2,788	599	2,077	938
Options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded from net income (loss) per share (in shares)	162	187	72	154
Unvested restricted stock awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded from net income (loss) per share (in shares)	208	130	232	240
Unvested restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded from net income (loss) per share (in shares)	2,324	238	1,709	495
ESPP
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded from net income (loss) per share (in shares)	94	44	64	49

Revenues (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
Revenues (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Revenue	$ 29,729	$ 35,211	$ 83,253	$ 124,148
Payment terms			75 days
Intent Marketing Solution
Disaggregation of Revenue [Line Items]
Revenue				$ 1,300

Revenues (Revenue Disaggregated by Geographic Location) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Revenue	$ 29,729	$ 35,211	$ 83,253	$ 124,148
United States
Disaggregation of Revenue [Line Items]
Revenue	19,731	22,689	54,201	78,350
International
Disaggregation of Revenue [Line Items]
Revenue	$ 9,998	$ 12,522	$ 29,052	$ 45,798

Revenues (Revenue Disaggregated by Sales Distribution Channel) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Revenues	$ 29,729	$ 35,211	$ 83,253	$ 124,148
Concentration risk, percentage	100.00%	100.00%	100.00%	100.00%
Desktop
Disaggregation of Revenue [Line Items]
Revenues	$ 12,481	$ 16,881	$ 40,453	$ 68,956
Concentration risk, percentage	42.00%	48.00%	49.00%	56.00%
Mobile
Disaggregation of Revenue [Line Items]
Revenues	$ 17,248	$ 18,330	$ 42,800	$ 55,192
Concentration risk, percentage	58.00%	52.00%	51.00%	44.00%

Fair Value Measurements (Financial Instruments) (Details) - Recurring - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 19,078	$ 1,807
Cash equivalents \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	19,078	210
Cash equivalents \| Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	1,597
Cash equivalents \| Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	1,999	25,098
Corporate debt securities \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Corporate debt securities \| Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	1,999	25,098
Corporate debt securities \| Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
U.S. Treasury, government and agency debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	12,487	29,901
U.S. Treasury, government and agency debt securities \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	12,487	29,901
U.S. Treasury, government and agency debt securities \| Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
U.S. Treasury, government and agency debt securities \| Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	$ 0	$ 0

Fair Value Measurements (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of goodwill	$ 0	$ 90,251	$ 0	$ 90,251
Goodwill		$ 0		$ 0
Cash equivalents \| Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 19,078		$ 19,078		$ 1,807
Income Approach Valuation Technique \| Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discounted cash flow rate		16.20%
Market Approach Valuation Technique \| Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Control premium		15.00%
EBITDA multiple		2.0

Other Balance Sheet Amounts (Investments in Marketable Securities) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Available-for-sale—short-term
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 14,500	$ 52,524
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(14)	(20)
Fair Value	14,486	52,504
Available-for-sale—short-term \| U.S. Treasury, government and agency debt securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	12,501	27,426
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(14)	(20)
Fair Value	12,487	27,406
Available-for-sale—short-term \| Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,999	25,098
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	$ 1,999	25,098
Available-for-sale — long-term \| U.S. Treasury, government and agency debt securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		2,504
Gross Unrealized Gains		0
Gross Unrealized Losses		(9)
Fair Value		$ 2,495

Other Balance Sheet Amounts (Narrative) (Details) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016
Balance Sheet Related Disclosures [Abstract]
Weighted remaining contractual maturity		2 months 12 days
Sales of available-for-sale securities		$ 9,228,000	$ 0
Unrealized gain (loss)	$ 0	0
Realized gain (loss)	0	0
Restricted cash	$ 0	$ 0		$ 0	$ 100,000

Other Balance Sheet Amounts (Accounts Payable and Accrued Expenses) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Balance Sheet Related Disclosures [Abstract]
Accounts payable—seller	$ 188,659	$ 203,694
Accounts payable—trade	5,081	3,764
Accrued employee-related payables	5,645	6,645
Accounts payable and accrued expenses	$ 199,385	$ 214,103

Intangible Assets (Finite-Lived Intangible Assets) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, gross	$ 17,588	$ 17,588
Total accumulated amortization—intangible assets	(6,617)	(4,229)
Total	10,971	13,359
Developed technology
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, gross	16,878	16,878
Total accumulated amortization—intangible assets	(6,182)	(4,062)
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, gross	690	690
Total accumulated amortization—intangible assets	(419)	(161)
Trademarks
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, gross	20	20
Total accumulated amortization—intangible assets	$ (16)	$ (6)

Intangible Assets (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense of intangible assets	$ 800	$ 1,200	$ 2,400	$ 3,500
Impairment of goodwill	$ 0	$ 90,251	$ 0	$ 90,251

Intangible Assets (Finite-Lived Intangible Assets, Future Amortization Expense) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Remaining 2018	$ 797
2019	3,010
2020	2,826
2021	2,826
2022	1,512
Thereafter	0
Total	$ 10,971	$ 13,359

Business Combinations (Narrative) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Jul. 14, 2017	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Business Acquisition [Line Items]
Impairment of goodwill		$ 0	$ 90,251	$ 0	$ 90,251
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Business Acquisition [Line Items]
Business Combination, Consideration Transferred	$ 38,600
Total net assets acquired	40,570
Cash and cash equivalents	$ 1,953
Business Combination In The Money Options Assumed	432,482
Business Combination Restricted Stock Assumed	77,499
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares	174,117
Business Combination, Acquisition Related Costs	$ 300
Business Combination Net Operating Loss Acquired	$ 9,300
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities			5,500		5,500
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Assets			3,800		$ 3,800
Impairment of goodwill			$ 90,300

Business Combinations (Allocated Purchase Price) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Jul. 14, 2017
Business Acquisition [Line Items]
Goodwill	$ 0
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Business Acquisition [Line Items]
Cash and cash equivalents		$ 1,953
Accounts receivable		256
Prepaid and other assets		18
Fixed assets		763
Other non-current assets		82
Intangible assets		14,840
Goodwill		24,546
Total assets acquired		42,458
Accounts payable and accrued expenses		78
Deferred revenue		91
Deferred tax liability, net		1,719
Total liabilities assumed		1,888
Total net assets acquired		$ 40,570

Business Combinations (Acquired Intangibles and Estimated Useful Life) (Details) - nToggle $ in Thousands	9 Months Ended
	Sep. 30, 2017 USD ($)
Business Acquisition [Line Items]
Total intangible assets acquired	$ 14,840
Developed technology
Business Acquisition [Line Items]
Total intangible assets acquired	$ 14,130
Estimated Useful Life	5 years
Non-compete agreements
Business Acquisition [Line Items]
Total intangible assets acquired	$ 690
Estimated Useful Life	2 years
Trademark & trade name
Business Acquisition [Line Items]
Total intangible assets acquired	$ 20
Estimated Useful Life	1 year 6 months

Business Combinations (Pro Forma) (Details) - nToggle - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017
Business Acquisition [Line Items]
Business Acquisition, Pro Forma Revenue	$ 35,270	$ 125,083
Business Acquisition, Pro Forma Net Income (Loss)	$ (103,895)	$ (134,665)

Stock-Based Compensation (Details)	9 Months Ended
Stock-Based Compensation (Details)	Sep. 30, 2018 shares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Number of shares available for grant	6,148,378
Number of Shares
Number of shares available for grant	6,148,378
Restricted awards
Number of Shares
Award vesting rights, percentage	25.00%
Stock Option
Number of Shares
Vesting period	4 years
Award vesting rights, percentage	25.00%
Restricted Stock Units (RSUs) \| Two Year RSUs
Number of Shares
Award vesting rights, percentage	50.00%
Number of awards granted	2,800,000

Stock-Based Compensation (Stock Options Outstanding) (Details) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2018 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance (in shares) \| shares	4,363
Granted (in shares) \| shares	706
Exercised (in shares) \| shares	(50)
Expired (in shares) \| shares	(1,239)
Forfeited (in shares) \| shares	(49)
Ending balance (in shares) \| shares	3,731
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Beginning balance (usd per share) \| $ / shares	$ 8.75
Granted (usd per share) \| $ / shares	2.09
Exercised (usd per share) \| $ / shares	0.91
Expired (usd per share) \| $ / shares	10.15
Forfeited (usd per share) \| $ / shares	4.54
Ending balance (usd per share) \| $ / shares	$ 7.18
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Outstanding	7 years
Outstanding, aggregate intrinsic value \| $	$ 1,469
Exercisable (in shares) \| shares	2,198
Exercisable (usd per share) \| $ / shares	$ 9.49
Exercisable	5 years 9 months 18 days
Exercisable, aggregate intrinsic value \| $	$ 467

Stock-Based Compensation (Stock Options Narrative) (Details)	9 Months Ended
	Sep. 30, 2018 USD ($) $ / shares
Number of Shares
Intrinsic values of options exercised	$ 100,000
Unrecognized employee stock-based compensation	$ 3,800,000
Weighted average grant date fair value \| $ / shares	$ 1.10
Fair value of options vested in period	$ 2,700,000
Stock Option
Number of Shares
Unrecognized employee stock-based compensation, period for recognition	2 years 6 months

Stock-Based Compensation (Valuation Assumptions) (Details) - Stock Option	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Number of Shares
Expected term (in years)	5 years 4 months 24 days	5 years 3 months 18 days	5 years 8 months 12 days	5 years 9 months 18 days
Risk-free interest rate	2.75%	1.88%	2.53%	2.03%
Expected volatility	55.00%	62.00%	57.00%	57.00%
Dividend yield	0.00%	0.00%	0.00%	0.00%

Stock-Based Compensation (Restricted Stock Activity) (Details) - Restricted Stock Awards shares in Thousands	9 Months Ended
	Sep. 30, 2018 $ / shares shares
Number of Shares
Beginning balance \| shares	558
Granted \| shares	0
Canceled \| shares	(156)
Vested \| shares	(176)
Ending balance \| shares	226
Weighted-Average Grant Date Fair Value
Beginning balance (in dollars per share) \| $ / shares	$ 12.60
Granted (in dollars per share) \| $ / shares	0
Canceled (in dollars per share) \| $ / shares	13.82
Vested (in dollars per share) \| $ / shares	11.81
Ending balance (in dollars per share) \| $ / shares	$ 12.37

Stock-Based Compensation (Restricted Stock Narrative) (Details) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2018 USD ($) $ / shares
Unvested restricted stock awards
Number of Shares
Fair value of restricted stock	$ 500
Unrecognized employee stock-based compensation	$ 1,100
Unrecognized employee stock-based compensation, period for recognition	1 year 2 months 12 days
Granted (in dollars per share) \| $ / shares	$ 0
Unvested restricted stock units
Number of Shares
Fair value of restricted stock	$ 1,800
Unrecognized employee stock-based compensation	$ 20,100
Unrecognized employee stock-based compensation, period for recognition	2 years 3 months 18 days
Granted (in dollars per share) \| $ / shares	$ 2.27
Intrinsic value of nonvested unit	$ 24,200

Stock-Based Compensation (Restricted Stock Units Activity) (Details) - Restricted Stock Units (RSUs) shares in Thousands	9 Months Ended
	Sep. 30, 2018 $ / shares shares
Number of Shares
Beginning balance \| shares	3,609
Granted \| shares	4,904
Canceled \| shares	(948)
Vested \| shares	(830)
Ending balance \| shares	6,735
Weighted-Average Grant Date Fair Value
Beginning balance (in dollars per share) \| $ / shares	$ 7.55
Granted (in dollars per share) \| $ / shares	2.27
Canceled (in dollars per share) \| $ / shares	5.27
Vested (in dollars per share) \| $ / shares	8.02
Ending balance (in dollars per share) \| $ / shares	$ 3.97

Stock-Based Compensation (Employee Stock Purchase Plan Narrative) (Details) - 2014 Employee Stock Purchase Plan - Employee Stock	9 Months Ended
	Sep. 30, 2018 shares
Number of Shares
Maximum employee subscription rate	10.00%
Purchase price of common stock, percent	85.00%
Number of shares reserved	1,692,373

Stock-Based Compensation (Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 3,860	$ 4,646	$ 13,016	$ 16,188
Cost of revenue
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	72	115	256	295
Sales and marketing
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	1,187	1,115	3,530	3,524
Technology and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	691	1,122	2,163	3,178
General and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	1,910	2,294	6,669	7,631
Restructuring and other exit costs
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 0	$ 0	$ 398	$ 1,560

Restructuring and Other Exit Costs - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and other exit costs	$ 0	$ 0	$ 3,440	$ 5,959
The 2017 Restructuring Events
Restructuring Cost and Reserve [Line Items]
Restructuring and other exit costs		$ 0		$ 6,000
Costs related to non-cash stock-based compensation			1,600
Accrued restructuring costs					$ 100
The 2018 Restructuring Events
Restructuring Cost and Reserve [Line Items]
Restructuring and other exit costs	0		3,440
Costs related to non-cash stock-based compensation			398
Accrued restructuring costs	$ 158		$ 158		$ 0

Restructuring and Other Exit Costs - Schedule of Restructuring and Other Exit Costs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Restructuring Reserve [Roll Forward]
Restructuring and other exit costs	$ 0	$ 0	$ 3,440	$ 5,959
The 2018 Restructuring Events
Restructuring Reserve [Roll Forward]
Accrued restructuring and other exit costs at December 31, 2017			0
Restructuring and other exit costs	0		3,440
Cash paid for restructuring and other exit costs			(2,884)
Non-cash stock-based compensation for restructuring and other exit costs			(398)
Accrued restructuring and other exit costs at September 30, 2018	$ 158		$ 158

Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Provision for income taxes	$ 84	$ (2,031)	$ 233	$ (1,510)
Provisional Transition Tax recorded due to Tax Act					$ 600
Provisional GILTI inclusion for ASC Topic 740			$ 1,200

Commitments and Contingencies (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Other Commitments [Line Items]
Rental expense	$ 3.2	$ 3.1	$ 9.7	$ 9.4
Expected future operating lease commitments	16.8		16.8
Data Centers For Cloud-Based Services
Other Commitments [Line Items]
Rental expense	1.6	$ 0.8	5.0	$ 3.6
Office Lease \| Financial Standby Letter of Credit
Other Commitments [Line Items]
Letters of credit outstanding, amount	$ 2.9		$ 2.9		$ 2.9

Debt (Details)	Sep. 26, 2018 USD ($)	Sep. 30, 2018 USD ($)
Line of Credit Facility [Line Items]
Adjusted Quick Ratio		1.2
Loan Agreement \| Revolving Credit Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity		$ 40,000,000.0
Available borrowing capacity		30,000,000.0
Borrowing capacity reserve		10,000,000.0
Capitalized debt issuance costs		$ 100,000
Unused capacity fee, percentage	0.15%
Adjusted Quick Ratio, in streamline period	1.05
Loan Agreement \| Revolving Credit Facility \| Compliance period, September 30, 2018 through June 30, 2019
Line of Credit Facility [Line Items]
Percentage of adjusted EBITDA	20.00%
Loan Agreement \| Revolving Credit Facility \| Compliance period, September 30, 2019
Line of Credit Facility [Line Items]
Adjusted EBITDA maximum	$ 1
Loan Agreement \| Revolving Credit Facility \| Compliance period, December 31, 2019 and thereafter
Line of Credit Facility [Line Items]
Adjusted EBITDA maximum	$ 5,000,000.0
Covenant Terms, Scenario One \| Loan Agreement \| Revolving Credit Facility
Line of Credit Facility [Line Items]
Adjusted Quick Ratio	1.00
Adjusted EBITDA maximum	$ 0
Covenant Terms, Scenario Two \| Loan Agreement \| Revolving Credit Facility
Line of Credit Facility [Line Items]
Adjusted Quick Ratio	0.90
Adjusted EBITDA minimum	$ 0
Streamline Period Applies \| London Interbank Offered Rate (LIBOR) \| Loan Agreement \| Revolving Credit Facility
Line of Credit Facility [Line Items]
Variable interest rate	2.50%
Streamline Period Applies \| Prime Rate \| Loan Agreement \| Revolving Credit Facility
Line of Credit Facility [Line Items]
Variable interest rate	0.50%
Streamline Period Does Not Apply \| London Interbank Offered Rate (LIBOR) \| Loan Agreement \| Revolving Credit Facility
Line of Credit Facility [Line Items]
Variable interest rate	4.00%
Streamline Period Does Not Apply \| Prime Rate \| Loan Agreement \| Revolving Credit Facility
Line of Credit Facility [Line Items]
Variable interest rate	2.00%

Label	Element	Value
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	$ 99,605,000