Roku (ROKU) 10-K 1 Mar 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Feb. 14, 2018	Jun. 30, 2017
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Trading Symbol	ROKU
Entity Registrant Name	Roku, Inc.
Entity Central Index Key	1,428,439
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Public Float			$ 0
Class A Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		19,746,394
Class B Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		79,823,487

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current Assets:
Cash	$ 177,250	$ 34,562
Accounts receivable, net of allowances of $17,739 and $16,213 as of December 31, 2017 and 2016, respectively	120,553	79,473
Inventories	32,740	43,568
Prepaid expenses and other current assets	11,367	4,981
Deferred cost of revenue	3,007	2,636
Total current assets	344,917	165,220
Property and equipment, net	14,736	9,528
Deferred cost of revenue, non-current portion	5,403	3,815
Intangible assets, net	2,030
Goodwill	1,382
Other non-current assets	3,429	515
Total Assets	371,897	179,078
Current Liabilities:
Accounts payable	56,413	31,397
Accrued liabilities	72,344	46,156
Current portion of long-term debt		15,000
Deferred revenue, current portion	34,501	23,952
Total current liabilities	163,258	116,505
Preferred stock warrant liability		9,990
Deferred revenue, non-current portion	48,511	29,084
Other long-term liabilities	7,849	4,143
Total Liabilities	219,618	159,722
Commitments and Contingencies (Note 8)
Convertible Preferred Stock:
Convertible preferred stock, $0.0001 par value 0 and 84,368 shares authorized as of December 31,2017 and 2016, respectively 0 and 80,844 shares issued and outstanding as of December 31,2017 and 2016, respectively		213,180
Stockholders’ Equity (Deficit):
Preferred stock, $0.0001 par value; 10,000 and 0 shares authorized as of December 31,2017 and 2016, respectively no shares issued and outstanding as of December 31,2017 and 2016, respectively
Common stock, $0.0001 par value 1,150,000 (Class A - 1,000,000 and Class B - 150,000) shares and 122,000 shares authorized as of December 31, 2017 and 2016, respectively 99,157 (Class A - 19,325 and Class B - 79,832) shares and 4,819 shares issued and outstanding as of December 31, 2017 and 2016, respectively	10	3
Additional paid-in capital	435,607	26,002
Accumulated deficit	(283,338)	(219,829)
Total stockholders’ equity (deficit)	152,279	(193,824)
Total Liabilities, Convertible Preferred Stock and Stockholders’ Equity (Deficit)	$ 371,897	$ 179,078

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounts receivable, allowances	$ 17,739	$ 16,213
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares authorized	0	84,368
Convertible preferred stock, shares issued	0	80,844
Convertible preferred stock, shares outstanding	0	80,844
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000	0
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	1,150,000	122,000
Common stock, shares issued	99,157	4,819
Common stock, shares outstanding	99,157	4,819
Class A Common Stock
Common stock, shares authorized	1,000,000
Common stock, shares issued	19,325
Common stock, shares outstanding	19,325
Class B Common Stock
Common stock, shares authorized	150,000
Common stock, shares issued	79,832
Common stock, shares outstanding	79,832

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 26, 2015
Net Revenue:
Total net revenue	$ 512,763	$ 398,649	$ 319,857
Cost of Revenue:
Total cost of revenue	312,930	277,604	230,079
Gross Profit:
Total gross profit	199,833	121,045	89,778
Operating Expenses:
Research and development	107,945	76,177	50,469
Sales and marketing	64,069	52,888	45,153
General and administrative	47,435	35,341	31,708
Total operating expenses	219,449	164,406	127,330
Loss from Operations	(19,616)	(43,361)	(37,552)
Other Income (Expense), Net:
Interest expense	(1,612)	146	(696)
Loss on extinguishment of debt	(2,338)
Change in fair value of preferred stock warrant liability	(40,333)	888	(1,768)
Other income (expense), net	705	(220)	(448)
Total other income (expense), net	(43,578)	814	(2,912)
Loss Before Income Taxes	(63,194)	(42,547)	(40,464)
Income tax expense	315	211	147
Net Loss Attributable to Common Stockholders	$ (63,509)	$ (42,758)	$ (40,611)
Net loss per share attributable to common stockholders—basic and diluted	$ (2.24)	$ (9.01)	$ (10.08)
Weighted-average shares used in computing net loss per share attributable to common stockholders—basic and diluted	28,308	4,746	4,030
Player
Net Revenue:
Total net revenue, Goods	$ 287,407	$ 293,929	$ 269,977
Cost of Revenue:
Total cost of revenue, Goods	258,104	249,821	221,416
Gross Profit:
Total gross profit	29,303	44,108	48,561
Platform
Net Revenue:
Total net revenue, Services	225,356	104,720	49,880
Cost of Revenue:
Total cost of revenue, Services	54,826	27,783	8,663
Gross Profit:
Total gross profit	$ 170,530	$ 76,937	$ 41,217

Consolidated Statements of Conv

Consolidated Statements of Convertible Preferred Stock And Stockholders' Equity (Deficit) - USD ($) shares in Thousands, $ in Thousands	Total	Convertible Preferred Stock	Common Stock	Additional Paid-in Capital	Treasury Stock	Accumulated Deficit
Balance at Dec. 27, 2014	$ (125,255)			$ 11,205		$ (136,460)
Balance, Shares at Dec. 27, 2014		75,475
Balance at Dec. 27, 2014		$ 165,099
Balance, Shares at Dec. 27, 2014			3,747
Issuance of Series D convertible preferred stock upon exercise of preferred stock warrants		$ 972
Issuance of Series D convertible preferred stock upon exercise of preferred stock warrants, Shares		409
Issuance of Series H convertible preferred stock in November at $9.17340 per share—net of issuance costs of $0.07 million		$ 45,432
Issuance of Series H convertible preferred stock, Shares		4,960
Reclassification of convertible preferred stock warrant liability to equity upon exercise of warrants		$ 1,677
Issuance of common stock upon exercise of stock options	837			837
Issuance of common stock upon exercise of stock options, Shares			784
Vesting of early exercised stock options	9			9
Stock-based compensation expense	5,284			5,284
Net loss	(40,611)					(40,611)
Balance at Dec. 26, 2015	(159,736)			17,335		(177,071)
Balance, shares at Dec. 26, 2015		80,844
Balance at Dec. 26, 2015		$ 213,180
Balance, Shares at Dec. 26, 2015			4,531
Issuance of common stock shares upon exercise of common and preferred warrants			162
Issuance of common stock upon exercise of stock options	438			438
Issuance of common stock upon exercise of stock options, Shares			126
Vesting of early exercised stock options	26			26
Stock-based compensation expense	8,206			8,206
Net loss	(42,758)					(42,758)
Balance at Dec. 31, 2016	$ (193,824)			26,005		(219,829)
Balance, shares at Dec. 31, 2016	80,844	80,844
Balance at Dec. 31, 2016	$ 213,180	$ 213,180
Balance, Shares at Dec. 31, 2016			4,819
Issuance of common stock shares upon exercise of common and preferred warrants			2,165
Issuance of common stock upon exercise of stock options	2,087		$ 1	2,086
Issuance of common stock upon exercise of stock options, Shares			963
Share repurchases	(671)				$ (671)
Share repurchases, shares			(92)
Vesting of early exercised stock options	62			62
Stock-based compensation expense	10,953			10,953
Issuance of common stock pursuant to an acquisition			108
Issuance of common stock pursuant to an initial public offering, net of issuance costs	131,646		$ 1	131,645
Issuance of common stock pursuant to an initial public offering, net of issuance costs, Shares			10,350
Conversion of preferred stock into common stock pursuant to an initial public offering	213,180	$ (213,180)	$ 8	213,172
Conversion of preferred stock into common stock pursuant to an initial public offering, Shares		(80,844)	80,844
Reclassification of preferred stock warrants liability to additional paid-in-capital upon conversion to common stock warrants	52,355			52,355
Net loss	(63,509)					(63,509)
Balance at Dec. 31, 2017	$ 152,279		$ 10	$ 436,278	$ (671)	$ (283,338)
Balance, shares at Dec. 31, 2017	0
Balance, Shares at Dec. 31, 2017			99,157

Consolidated Statements of Con6

Consolidated Statements of Convertible Preferred Stock And Stockholders' Equity (Deficit) (Parenthetical) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Nov. 30, 2015	Dec. 31, 2017
Convertible preferred stock, par value		$ 0.0001
Initial public offering issuance cost		$ 3,100
Series H Convertible Preferred Stock
Convertible preferred stock, par value	$ 9.17340
Stock issuance cost	$ 70

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 26, 2015
Cash flows from operating activities:
Net loss	$ (63,509)	$ (42,758)	$ (40,611)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	5,336	5,302	2,555
Impairment of assets		320
Stock-based compensation expense	10,953	8,206	5,284
Provision for doubtful accounts	104	336	663
Change in fair value of preferred stock warrant liability	40,333	(888)	1,768
Noncash interest expense	784	115	354
Loss on disposals of property and equipment	54	29	137
Loss from exit of facilities	525	3,804
Loss from extinguishment of debt	2,338
Write-off of deferred initial public offering costs		594	1,609
Changes in operating assets and liabilities:
Accounts receivable	(41,184)	(26,354)	(14,118)
Inventories	10,828	(13,256)	(3,754)
Prepaid expenses and other current assets	(6,514)	(544)	(1,887)
Deferred cost of revenue	(1,959)	(2,885)	(3,017)
Other noncurrent assets	(2,794)	448	1,179
Accounts payable	24,315	(2,808)	4,724
Accrued liabilities	24,127	17,796	2,802
Other long-term liabilities	3,579	294	1,391
Deferred revenue	29,976	19,786	8,317
Net cash provided by (used in) operating activities	37,292	(32,463)	(32,604)
Cash flows from investing activities:
Purchase of property and equipment	(9,229)	(8,596)	(5,019)
Purchase of business, net of cash acquired	(2,959)
Change in deposits	(80)	29	(186)
Net cash used in investing activities	(12,268)	(8,567)	(5,205)
Cash flows from financing activities:
Payments of costs related to initial public offering		(594)	(1,120)
Proceeds from borrowings	24,691	15,000	15,000
Repayments of borrowings	(40,446)	(15,000)	(2,576)
Proceeds from exercise of stock options, net of repurchases	1,773	438	839
Proceeds from issuance of common stock pursuant to an initial public offering, net of issuance costs of $3.1 million	131,646
Proceeds from exercise of preferred stock warrants			972
Proceeds from issuance of convertible preferred stock			45,500
Issuance costs in connection with issuance of convertible preferred stock			(68)
Net cash provided by (used in) financing activities	117,664	(156)	58,547
Net Increase (Decrease) In Cash	142,688	(41,186)	20,738
Cash—Beginning of period	34,562	75,748	55,010
Cash—End of period	177,250	34,562	75,748
Supplemental disclosures of cash flow information:
Cash paid for interest	1,149	236	273
Cash paid for income taxes	222	121	83
Supplemental disclosures of noncash investing and financing activities:
Purchases of property and equipment recorded in accounts payable and accrued liabilities	1,250	$ 306	1,608
Fair value of preferred stock warrants reclassified to additional paid in capital	52,355		$ 1,677
Issuance of convertible preferred stock warrants in connection with debt	$ 2,032

Consolidated Statements of Cas8

Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	Oct. 02, 2017	Dec. 31, 2017	Dec. 26, 2015
Issuance costs in connection with issuance of common stock			$ 68
Initial Public Offering | Class A Common Stock
Issuance costs in connection with issuance of common stock	$ 3,100	$ 3,100

The Company

The Company	12 Months Ended
	Dec. 31, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
The Company	1. THE COMPANY Organization and Description of Business Roku, Inc. (the “Company” or “Roku”), was formed in October 2002 as Roku LLC under the laws of the State of Delaware. On February 1, 2008, Roku LLC was converted into Roku, Inc., a Delaware corporation. The Company’s TV streaming platform allows users to easily discover and access a wide variety of movies and TV episodes, as well as live sports, music, news and more. The Company operates in two reportable segments and generates revenue through the sale of streaming players, advertising, subscription and transaction revenue sharing, as well as through licensing arrangements with TV brands and cable, satellite, and telecommunication service operators (“service operators”). Initial Public Offering On October 2, 2017, the Company completed its initial public offering (“IPO”) of Class A common stock, in which it sold 10.4 million shares, including 1.4 million shares pursuant to the underwriters’ over-allotment option. The shares were sold at an IPO price of $14.00 per share for net proceeds of $134.8 million, after deducting underwriting discounts and commissions of $10.1 million. Additionally, offering costs incurred by the Company were $3.1 million. Upon the closing of the Company’s IPO, all outstanding shares of its convertible preferred stock automatically converted into 80.8 million shares of Class B common stock and all outstanding convertible preferred stock warrants automatically converted to Class B common stock warrants on a one-for-one basis. Following the IPO, we have two classes of authorized common stock – Class A common stock and Class B common stock. Class A common stock entitles holders to one vote per share, and Class B common stock entitles holders to 10 votes per share.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation and Principles of Consolidation The consolidated financial statements, which include the accounts of Roku, Inc. and its wholly-owned subsidiaries, have been prepared in conformity with accounting principles generally accepted in the United States (“U.S. GAAP”). All intercompany accounts and transactions have been eliminated in consolidation. Fiscal Year Prior to 2017, the Company’s fiscal year was the 52- or 53-week period that ended on the last Saturday of December. The fiscal years 2015 and 2016 ended on December 26, 2015 and December 31, 2016, respectively. In 2017, the Company changed the fiscal year-end to match the calendar year-end. Fiscal year 2015 spanned 52 weeks and fiscal year 2016 spanned 53 weeks. Use of Estimates The preparation of the Company’s consolidated financial statements in accordance with U.S. GAAP requires management to make certain estimates, judgments, and assumptions that affect the reported amounts of assets and liabilities and related disclosures at the date of the financial statements, as well as the reported amounts of revenue and expenses during the periods presented. Significant items subject to such estimates include revenue recognition for multiple element arrangements, determination of revenue reporting as net versus gross, sales return reserves, customer incentive programs, inventory valuation, the valuation of deferred income tax assets, the recognition and disclosure of contingent liabilities, stock-based compensation and the fair value of assets and liabilities acquired in business combinations. The Company bases its estimates on historical experience and on various other assumptions that the Company believes to be reasonable under the circumstances. Actual results may differ from the Company’s estimates. Comprehensive Loss Comprehensive loss is equal to the net loss for all periods presented. Therefore, the consolidated statements of comprehensive loss have been omitted from the consolidated financial statements. Foreign Currency The functional currency of the Company’s foreign subsidiaries is the U.S. dollar. Monetary assets and liabilities of these subsidiaries are remeasured into U.S. dollars from the local currency at rates in effect at period-end and nonmonetary assets and liabilities are remeasured at historical rates. Revenues and expenses are remeasured at average exchange rates in effect during each period. Foreign currency gains or losses from re-measurement and transaction gains or losses are recorded as other income (expense), net in the consolidated statements of operations. During the years ended December 31, 2017 and 2016, the Company recorded foreign currency gain of $0.1 million and foreign currency loss of $0.4 million, respectively. Concentrations Financial instruments, which potentially subject the Company to concentrations of credit risk, consist principally of cash and accounts receivable. As of December 31, 2017 and 2016, 95% and 94% of the Company’s cash balances were managed by one financial institution. Accounts receivable are typically unsecured and are derived from revenue earned from customers. They are stated at invoice value less estimated allowances for returns, customer incentives and doubtful accounts. The Company performs ongoing credit evaluations of its customers and maintains allowances for potential credit losses. Customers accounting for 10% or more of the Company’s net revenue were as follows Year Ended December 31, 2017 December 31, 2016 December 26, 2015 Customer A * % 13 % 16 % Customer B 10 12 15 Customer C 20 24 23 Customer E 10 * * Customers accounting for 10% or more of the Company’s accounts receivable were as follows: December 31, 2017 December 31, 2016 Customer A * % 12 % Customer B * 11 Customer C * 17 Customer D 16 17 * Less than 10% Business Combinations We determine the fair value of the assets acquired and liabilities assumed based on their estimated fair values as of the date of acquisition. Goodwill is measured at the acquisition Any contingent consideration payable is recognized at fair value at the acquisition date. Liability-classified contingent consideration is remeasured each reporting period with changes in fair value recognized in earnings until the contingent consideration is settled. When we issue payments or grants of equity to selling shareholders in connection with an acquisition, we evaluate whether the payments or awards are compensatory. This evaluation includes whether cash payments or stock award vesting is contingent on the continued employment of the selling stockholder beyond the acquisition date. If continued employment is required for the cash to be paid or stock awards to vest, the award is treated as compensation for post-acquisition services and is recognized as compensation expense. Acquisition related costs incurred in connection with a business combination, other than those associated with the issuance of debt or equity securities, are expensed as incurred. Goodwill, Purchased Intangible Assets and Impairment Assessment Goodwill represents the excess of the purchase price over the fair value of the assets acquired and liabilities assumed, if any, in a business combination. The Company reviews its goodwill for impairment annually, as of the beginning of the fourth quarter, and whenever events or changes in circumstances indicate that impairment may exist. The Company did not recognize any impairment of goodwill in the year ended December 31, 2017. Purchased intangible assets consist primarily of developed technology. Purchased intangible assets are recorded at fair value on the date of acquisition and amortized over their estimated useful lives following the pattern in which the economic benefits of the assets will be consumed, generally straight-line. The carrying amounts of our purchased intangible assets are periodically reviewed for impairment whenever events or changes in circumstances indicate that the carrying value of these assets may not be recoverable or that the useful life is shorter than originally estimated. Impairment of Long-Lived Assets The Company’s long-lived assets include property and equipment and other noncurrent assets and are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recovered. Recoverability of assets is measured first by comparing their carrying amounts to their future undiscounted net cash flows. If such assets are considered to be impaired, the impairment to be recognized equals the amount by which the carrying value of the asset exceeds its fair market value. No impairment was recorded during the year ended December 31, 2017. The Company recorded an impairment of $0.3 million for obsolete internal-use software during the year ended December 31, 2016. Fair Value of Financial Instruments The Company defines fair value as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The Company applies fair value accounting for all assets and liabilities that are recognized or disclosed at fair value in the consolidated financial statements on a recurring basis. The carrying amounts reported in the consolidated financial statements for cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities approximate their fair values due to their short-term nature. Inventories The Company’s inventories consist primarily of finished goods and are stated at the lower of cost or market with cost determined on a first-in, first-out basis and market based on net realizable value. If the cost of the inventories exceeds their net realizable value, provisions are made currently for the difference between the cost and the market value. The Company evaluates inventory levels and purchase commitments for excess and obsolete products, based on management’s assessment of future demand and market conditions. Property and Equipment Property and equipment are recorded at cost and depreciated using the straight-line method over their estimated useful lives of the assets, generally ranging between eighteen months and five years. Leasehold improvements are amortized over the shorter of the lease term or their estimated useful lives, which is generally five years. Website and Internal-Use Software The Company capitalizes costs to develop its website and internal-use software. The Company expenses all costs that relate to the planning and post-implementation phases of development as incurred. The Company capitalizes subsequent costs when preliminary efforts are successfully completed, management has authorized and committed project funding, and it is probable that the project will be completed and will be used as intended. Costs incurred for enhancements that are expected to result in additional material functionality are capitalized. During the years ended December 31, 2017, 2016 and December 26, 2015, the Company capitalized website and internal-use software development costs of $2.6 million, $1.8 million and $0.7 million, respectively. Capitalized costs are amortized using the straight-line method over an estimated useful life of the asset, which is generally two years, beginning when the asset is ready for its intended use. During the years ended December 31, 2017, 2016 and December 26, 2015, the Company amortized expenses of $1.1 million, $0.7 million and $0.3 million, respectively. Streaming Content The Company licenses certain content for users to access through The Roku Channel. The content licenses can be for a fixed fee and/or advertising revenue share with specific windows of content availability. The Company capitalizes the content license fees and records a corresponding liability when the license period begins, the cost of the content is known and the content is accepted and available for streaming. The Company amortizes the content assets into “Cost of Revenue, Platform” over the contractual window of availability. At December 31, license fees included in “Prepaid expenses and other current assets” are not material. Revenue Recognition The Company derives revenue primarily from sales of its players and platform services. Revenue is recognized when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the price is fixed or determinable, and collectability is reasonably assured. Multiple Element Arrangements —The Company commonly enters into multiple-element arrangements. In such arrangements, the Company will combine arrangement deliverables into units of accounting and allocate the total arrangement consideration to the different units of accounting based on a relative selling price hierarchy. To determine the relative selling price of each element, the Company uses vendor-specific objective evidence of fair value (“VSOE”), if available, third party evidence (“TPE”), if VSOE is not available, or best estimated selling price (“BESP”), if neither VSOE nor TPE are available. The objective of BESP is to determine the price at which the Company would transact a sale if the product or service were available on a standalone basis. The Company establishes BESP considering multiple factors including, but not limited to, historical prices of products sold on a stand-alone basis, cost and gross margin objectives, competitive pricing practices and customer and market specific considerations. Revenue is recognized for each unit of accounting provided that all revenue recognition criteria have been met. Players —The Company sells the majority of its players through consumer retail distribution channels, including brick and mortar and online retailers, and through the Company’s website. For sales through consumer retail distribution channels, revenue recognition occurs when title and risk of loss have transferred to the customer which usually occurs upon shipment to the customers or receipt of the products by the customer depending on shipping terms. The Company establishes allowances for expected product returns and these allowances are recorded as a direct reduction to revenue. Return allowances are based on the Company’s historical experience. Certain payments to retailers and distributors such as market development funds, store promotions and price protection are recorded as a reduction of revenue. The Company reduces revenue at the later of the date at which the related player revenue is recognized or the date on which the program is offered. On occasion, these allowances cannot be reasonably and reliably estimated. Player revenue is then recognized at the time the players sell through to the end customer. The Company’s player sales include two units of accounting: hardware, which includes embedded software, and unspecified upgrades or enhancements on a when-and-if available basis. The Company has determined that its hardware and embedded software be considered as one single unit of accounting, because the hardware and software individually do not have standalone value and are not sold separately. The Company initially records the relative selling price of the unspecified upgrades or enhancements on a when-and-if-available basis as deferred revenue, and then recognizes the deferred revenue into player, net revenue ratably on a straight-line basis over the estimated economic life of the associated players. Shipping charges billed to customers are included in player revenue and the related shipping costs are included in cost of player revenue. Revenue is recorded net of taxes collected or accrued. Sales taxes are recorded as current liabilities until remitted to the relevant government authority. Platform —The Company earns platform revenue from fees received from advertisers and content publishers and licensing its technology and proprietary operating system to service operators and TV brands. Platform revenue primarily includes fees earned or derived from the sale of digital advertising, revenue sharing with content publishers for new or recurring user subscriptions activated through the Company’s platform and revenue share from user purchases of content publishers’ media through its platform. The Company also earns revenue from the sale of branded channel buttons on remote controls. Licensing revenues from service operators are mostly generated from unit activation or flat fees and ongoing maintenance fees. Licensing revenues from TV brands are generated on a flat fee basis or from per unit licensing fees earned. Digital advertising includes video and display ads that are served on the Company’s platform. Digital advertising revenue consists of video and display advertising commonly sold on a cost per thousand impression basis. Advertising revenue arrangements are evidenced by a fully executed insertion order. Revenue is recognized in the period the impressions and promotional media are delivered. Fees derived from the Company’s billing services supporting new or recurring user subscriptions activated through its platform and from purchases of content publishers’ media are recognized as transacted at the net amount retained by the Company, generally equal to a fixed percentage of the price charged by the content provider or a contractual flat fee. When the content publisher is responsible for user billing, the Company recognizes revenue from its share of the fees on an as reported basis, in arrears, on a monthly or quarterly basis. The Company also earns fees through the sale of branded channel buttons on remote controls. These branded buttons provide one-touch, direct access to the providers’ content on the Company’s platform. The Company typically receives a fixed fee per button unit, and revenue is recognized as remote controls are shipped by the Company or reported as shipped by TV brands. Revenues earned from service operators and TV brands in the licensing of the Company’s technology and proprietary operating system are accounted for under software revenue recognition guidance. The Company has been unable to establish VSOE for any component of these licensing arrangements and therefore these arrangements are accounted for as a single unit of accounting and revenue over the term of the relationship. Arrangements with service operators are generally comprised of a license for the technology and proprietary operating system, unspecified upgrades or enhancements, hosting of a branded channel store, and engineering and support services. Arrangements with TV brands commonly include a license to the technology and proprietary operating system over a specified term including updates and upgrades. Deferred Revenue and Deferred Cost of Revenue The Company’s deferred revenue reflect fees received from licensing and service arrangements, including advertising, that will be recognized as revenue over time or as services are rendered. Deferred revenue balances consist of the amount of player sales allocated to unspecified upgrades or enhancements on a when-and-if available basis, licensing and services fees from service operators and TV brands, and payments from advertisers and content publishers. Deferred cost of revenue consists of amounts associated with related deferred revenues and is recognized as cost of revenue in the same manner as its respective deferred revenue. Deferred revenue and the associated deferred cost of revenue expected to be realized within one year are classified as current liabilities and current assets, respectively, and the remaining are recorded as noncurrent liabilities and noncurrent assets, respectively. Warranty Costs The Company generally provides for the estimated cost of hardware and software warranties at the time the related revenue is recognized. The Company assesses the adequacy of its preexisting warranty liabilities and adjusts the amounts as necessary based on actual experience and changes in future estimates. Advertising Costs Advertising costs are expensed when incurred and are included in sales and marketing expense in the consolidated statements of operations. The Company incurred advertising costs of $3.4 million, $3.9 million and $4.1 million for the years December 31, 2017, 2016 and December 26, 2015 respectively. Stock-Based Compensation The Company measures compensation expense for all stock-based awards, including stock options and restricted stock units granted to employees, based on the estimated fair value on the date of grant. The fair value of each stock option granted is estimated using Black-Scholes option-pricing model. Stock-based compensation is recognized on a straight-line basis over the requisite vesting period. For the years ended December 31, 2016, and December 26, 2015 the stock-based compensation was recorded net of estimated forfeitures using a forfeiture rate based on an analysis of the Company’s actual historical forfeitures. The Company adopted new guidance effective January 1, 2017 to recognize forfeitures as they occur. The Company accounts for stock options issued to nonemployees based on the fair value of the awards determined using the Black-Scholes option-pricing model. The fair value of stock options granted to nonemployees is remeasured as the stock options vest, and the resulting change in fair value, if any, is recognized in the Company’s consolidated statements of operations during the period the related services are rendered, generally four years. The Company accounts for restricted stock units issued to employees based on the grant date fair value which is determined based on the closing market price of the Class A common stock on the date of grant. The expense is recognized in the Company’s consolidated statement of operations on a straight-line basis over the requisite vesting period. Income Taxes The Company accounts for income taxes using an asset and liability approach. Deferred tax assets and liabilities are determined based on the difference between the consolidated financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to affect taxable income. Valuation allowances are established when necessary to reduce deferred tax assets to the amounts that are more likely than not to be realized. Net Loss per Share Since the Company was in a loss position for all periods presented, basic net loss per share is the same as diluted net loss per share for all periods as the inclusion of all potential common shares outstanding and potentially dilutive securities would have been anti-dilutive. Recent Accounting Pronouncements In January 2017, the FASB issued ASU 2017-04, Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment, In January 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business, In October 2016, the FASB issued ASU 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force), In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), In January 2016, the FASB issued ASU 2016-01, Financial Instruments—Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities, In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606), The Company is currently in the process of finalizing the impact of the new standard on its accounting policies, processes and system requirements. Furthermore, the Company has made and will continue to make investments in systems to enable timely and accurate reporting under the new standard. The Company expects that the adjustment from the adoption will result in a decrease to the accumulated deficit in the range of $32.0 million to $42.0 million. The Company believes that the new standard will impact accounting for revenue arrangements as follows: • Revenue from the licensing of the Company’s technology and proprietary operating system to service operators and TV brands, will be recognized earlier and could result in greater variability in revenue recognition; • Revenue resulting from the variable consideration (e.g. revenue share from user subscriptions and media purchases through the platform or sale of branded channel buttons on its remote controls) outlined in content publisher arrangements is estimated and allocated for the entire contract period and then recognized based on the percentage of completion across various performance obligations; and • Expanded disclosures. The Company expects revenue recognition related to players and advertising to remain relatively unchanged under the new guidance.

Business Combination

Business Combination	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Business Combinations	3. business combination On September 6, 2017, the Company acquired all of the outstanding shares of a privately held technology company located in Denmark to enhance the Company’s player product offering, for an aggregate purchase price of $3.5 million. The Company paid $3.0 million of the aggregate purchase price at the time of acquisition with $0.5 million payable one year after acquisition date. In addition, the Company issued 0.1 million shares of its Class B common stock to two of the founders as part of a continuing services arrangement. The shares are subject to a right of repurchase which lapses over a three year period at varying prices per share. In addition, the Company incurred approximately $0.4 million of costs related to the acquisition which is included in the general and administrative expenses. The preliminary purchase price allocation includes $1.4 million of goodwill and $2.2 million of identifiable intangible assets, which primarily consist of developed technology, with an expected useful life of approximately four years. Goodwill represents the excess of the purchase price over the fair value of the net tangible and intangible assets acquired, and is not expected to be deductible for income tax purposes. The goodwill in this transaction is primarily attributable to the acquired workforce and expected operating synergies. The results of operations of the acquired company are included in the results of the Company beginning on the date the acquisition was completed. Actual and pro forma results of operations have not been presented as the total amounts of revenue and net income are not material to the Company's consolidated results for all periods presented. The Company recorded an expense of $0.2 million for amortization of intangible asset during the year ended December 31, 2017. The estimated future amortization expenses for intangible asset is $0.6 million, $0.6 million, $0.5 million and $0.3 million for the years ending in December 31, 2018, 2019, 2020 and 2021, respectively.

Balance Sheet Components

Balance Sheet Components	12 Months Ended
	Dec. 31, 2017
Balance Sheet Related Disclosures [Abstract]
Consolidated Balance Sheet Components	4. Balance sheet components Balance sheet components consisted of the following: Accounts Receivable, net : Accounts receivable, net consisted of the following: December 31, 2017 December 31, 2016 (in thousands) Gross accounts receivable $ 138,292 $ 95,686 Allowance for sales returns (6,907 ) (6,916 ) Allowance for sales incentives (10,442 ) (8,503 ) Other allowances (390 ) (794 ) Total allowances (17,739 ) (16,213 ) Total Accounts Receivable—net $ 120,553 $ 79,473 Allowance for Sales Returns : Allowance for sales returns consist of the following activities: December 31, 2017 December 31, 2016 (in thousands) Beginning balance $ (6,916 ) $ (9,514 ) Charged to revenue (19,089 ) (20,810 ) Utilization of sales return reserve 19,098 23,408 Ending balance $ (6,907 ) $ (6,916 ) Allowance for Sales Incentive : Allowance for sales incentive consisted of the following activities: December 31, 2017 December 31, 2016 (in thousands) Beginning balance $ (8,503 ) $ (7,642 ) Charged to revenue (44,264 ) (36,626 ) Utilization of sales incentive reserve 42,325 35,765 Ending balance $ (10,442 ) $ (8,503 ) Property and Equipment, net : Property and equipment, net consisted of the following: December 31, 2017 December 31, 2016 (in thousands) Computers and equipment $ 11,631 $ 8,787 Leasehold improvements 8,437 4,201 Website and internal-use software 5,461 2,902 Office equipment and furniture 1,987 1,452 Total property and equipment 27,516 17,342 Accumulated depreciation and amortization (12,780 ) (7,814 ) Property and Equipment, net $ 14,736 $ 9,528 Depreciation and amortization expense for the years ended December 31, 2017, 2016 and December 26, 2015 was $5.2 million, $5.3 million and $2.6 million, respectively. Accrued Liabilities : Accrued liabilities consisted of the following: December 31, 2017 December 31, 2016 (in thousands) Accrued royalty expense $ 17,165 $ 14,940 Accrued inventory 2,382 4,274 Accrued payroll and related expenses 8,699 5,342 Accrued cost of revenue 12,210 7,264 Accrued payments to content publishers 24,037 8,554 Sales tax and tax related liabilities 751 769 Other accrued expenses 7,100 5,013 Total Accrued Liabilities $ 72,344 $ 46,156 Deferred Revenue : Deferred revenue consisted of the following: December 31, 2017 December 31, 2016 (in thousands) Player, current $ 15,479 $ 13,611 Platform, current 19,022 10,341 Total deferred revenue, current 34,501 23,952 Player, non-current 5,837 5,215 Platform, non-current 42,674 23,869 Total deferred revenue, non-current 48,511 29,084 Total Deferred Revenue $ 83,012 $ 53,036

Fair Value Disclosure

Fair Value Disclosure	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Disclosure	5. FAIR VALUE DISCLOSURE Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in the principal market (or most advantageous market, in the absence of a principal market) for the asset or liability in an orderly transaction between market participants at the measurement date. Further, entities are required to maximize the use of observable inputs and minimize the use of unobservable inputs in measuring fair value, and to utilize a three-level fair value hierarchy that prioritizes the inputs used to measure fair value. The three levels of inputs used to measure fair value are as follows: • Level 1 — Quoted prices in active markets for identical assets or liabilities. Financial assets and liabilities measured using Level 1 inputs include accounts receivable, prepaid expenses, accounts payable and accrued liabilities. • Level 2 — Observable inputs other than quoted prices included within Level 1, including quoted prices for similar assets or liabilities in active markets; quoted prices for identical or similar assets or liabilities in markets that are not active; and inputs other than quoted prices that are observable or are derived principally from, or corroborated by, observable market data by correlation or other means. The Company does not use Level 2 inputs to measure any assets or liabilities. • Level 3 — Unobservable inputs that are supported by little or no market activity, are significant to the fair value of the assets or liabilities, and reflect the Company’s own assumptions about the assumptions market participants would use in pricing the asset or liability developed based on the best information available in the circumstances. The Company’s preferred stock warrant liability was measured at fair value using Level 3 inputs upon issuance and at each reporting date. Inputs used to determine the estimated fair value of the warrant liability as of the valuation date included remaining contractual term of the warrants, the risk-free interest rate, the volatility of comparable public companies over the remaining term, and the fair value of underlying shares. The significant unobservable inputs used in the fair value measurement of the preferred stock warrant liability were the fair value of the underlying stock at the valuation date and the estimated term of the warrants. Generally, increases (decreases) in the fair value of the underlying stock and estimated term would result in a directionally similar impact to the fair value measurement. The Company did not have an outstanding preferred warrant liability as of December 31, 2017 as all preferred stock warrants were converted into common stock warrants pursuant to the IPO. A reconciliation of the preferred stock warrant liability measured and recorded at fair value on a recurring basis using significant unobservable inputs is as follows: Year Ended December 31, 2017 December 31, 2016 December 26, 2015 (in thousands) Convertible preferred stock warrant liability — beginning balance $ 9,990 $ 10,878 $ 10,787 Fair value of new warrants issued 2,032 — — Change in fair value* 40,333 (888 ) 1,768 Reclassification to preferred stock upon exercise — — (1,677 ) Reclassification to APIC upon conversion to common warrants (52,355 ) — — Convertible preferred stock warrant liability — ending balance $ — $ 9,990 $ 10,878 * Recognized in the consolidated statements of operations within other expense—net. Assets and liabilities that are measured at fair value on a non-recurring basis Non-financial assets such as goodwill, intangible assets, and property, plant, and equipment are evaluated for impairment and adjusted to fair value using Level 3 inputs, only when impairment is recognized. There were no indicators of impairment that required a fair value analysis during the years ended December 31, 2017 and 2016.

Debt

Debt	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Debt	6. DEBT Bank—Term Loan In July 2011, the Company amended its loan and security agreement (the “LSA”) with a financial institution (the “Bank”). The LSA provided for a term loan borrowing of $5.0 million, and a revolving line of credit of up to $7.5 million, both of which could be drawn on under certain conditions. The Company borrowed $4.5 million in July 2011. Advances under the term loan incurred a financing payment equal to 2% of the advance payable at the end of the loan, in addition to quarterly interest payments at a fixed annual rate of 10%. Borrowings on the line of credit bore interest at a premium of 1.75% over the bank’s prime rate. The length of the term loan borrowing was 48 months, and the length of the revolving line of credit was 12 months. The LSA was secured by all assets of the Company and the Company repaid the loan in July 2015. The Company had previously amended the LSA at various dates and, in November 2014, replaced the LSA with an amended and restated loan and security agreement (the “Restated 2014 LSA”) providing advances under the revolving line of credit up to $30.0 million and extending the line of credit to September 30, 2016. Additionally, the Restated 2014 LSA provides for letters of credit to be issued up to the lesser of the available line of credit, reduced by outstanding advances and drawn but unreimbursed letters of credit, or $5.0 million. The Restated 2014 LSA agreement contains a financial covenant to maintain a minimum required adjusted quick ratio (calculated as the sum of cash maintained with the Bank and the Bank’s affiliates and net billed account receivable balances, divided by current liabilities plus all outstanding obligations to the Bank under the revolving line, less deferred revenue), and non-financial covenants including providing the audited annual financial statements to the bank within 180 days following the year end. In May 2015, the Company entered into a first amendment to the Restated 2014 LSA with the Bank. The advances under the first amendment to the Restated LSA carry a floating per annum interest rate equal to the prime rate or the prime rate plus 2.5% depending on certain ratios. The first amendment further changed the financial covenant to maintain a current ratio (calculated as current assets, divided by current liabilities less deferred revenue), greater than or equal to 1.1. In June 2017, the Company entered into a second amendment to the Restated 2014 LSA. The advances under the second amendment carry a floating per annum interest rate equal to, at the Company’s option, (1) the prime rate or (2) LIBOR plus 2.75%, or the prime rate plus 1% depending on certain ratios. The extension further changed the financial covenant to maintain a current ratio (calculated as current assets, divided by current liabilities less deferred revenue) greater than or equal to 1.25. The revolving line of credit terminates on June 30, 2019 at which time the principal amount of all outstanding advances becomes due and payable. As of December 31, 2017 and 2016, the Company was in compliance with all of the covenants in the amended Restated 2014 LSA. The interest rate on the line of credit was 4.31% as of December 31, 2017 and 3.75% as of December 31, 2016. The Company had $0 and $15.0 million outstanding under the line of credit as of December 31, 2017 and 2016, respectively. The Company had $1.5 million and $0.9 million outstanding as letters of credit as of December 31, 2017 and 2016, respectively In June 2017, the Company entered into a subordinated loan agreement (“2017 Agreement”) with the Bank. The 2017 Agreement provides for a term loan borrowing of $40.0 million, with a minimum of $25.0 million to be initially drawn at the close of the agreement and the remaining amount available for a 24 month period, to be drawn in no less than $5.0 million increments. Advances under the term loan incur a facility fee equal to 1% of the drawn borrowings, in addition to interest payments at an interest rate equal to, at the Company’s option, (1) the prime rate plus 3.5% or (2) LIBOR plus 6.5%, subject to a 1% LIBOR floor. Additionally, the borrowings incur payment in kind interest fees equal to 2.5%, accruing to the unpaid borrowings balance, compounded monthly. Payment in kind interest may be settled in cash, at the Company’s election, during the term or at maturity. The Company is also obligated to pay final payment fees ranging from 1% to 4% depending on the timing of the payment. The 2017 Agreement terminates on October 9, 2020. On October 31, 2017 the Company repaid the entire amount outstanding, and subsequently terminated the 2017 Agreement. The Company recorded a loss of $2.3 million as a result of early extinguishment of debt. In connection with the 2017 Agreement the Company issued 0.4 million warrants to purchase shares of Series H convertible preferred stock, with an exercise price of $9.17340. The warrants are exercisable up to ten years from the date of issuance. Upon the repayment of the amounts borrowed and the subsequent termination of the 2017 Agreement, the Company cancelled 0.1 million warrants to purchase Class B common stock that were contingent on future borrowings.

Stockholders' Equity (Deficit)

Stockholders' Equity (Deficit)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Stockholders' Equity (Deficit)	7. STOCKHOLDERS’ EQUITY (DEFICIT) Convertible Preferred Stock As of December 31, 2016 convertible preferred stock consisted of the following: December 31, 2016 Series Price Shares Authorized Shares Outstanding Liquidation Preference (in thousands, except price per share data) A $ 0.36312 23,020 23,020 $ 8,359 B 0.93808 6,396 6,396 6,000 C-1 0.54109 9,240 9,240 5,000 C-2 0.64931 8,950 7,700 5,000 D 2.37840 4,686 4,205 10,000 E 4.35679 11,161 11,075 48,250 F 5.43396 11,042 11,042 60,000 G 7.79730 3,206 3,206 25,000 H 9.17340 6,667 4,960 45,500 Total 84,368 80,844 $ 213,109 Upon the closing of the Company’s IPO, all outstanding shares of its convertible preferred stock automatically converted into 80.8 million shares of Class B common stock on a one-to-one basis. On October 2, 2017, the Company filed an Amended and Restated Certificate of Incorporation, which authorized the issuance 10 million shares of undesignated preferred stock with rights and preferences determined by the Company’s Board of Directors (the “Board”) at the time of issuance of such shares. As of December 31, 2017, there were no shares of preferred stock issued and outstanding Common Stock The Company’s Amended and Restated Certificate of Incorporation filed on October 2, 2017, established two classes of authorized common stock, Class A common stock and Class B common stock. All shares of common stock outstanding immediately prior to the IPO, including shares of common stock issued upon the conversion of the convertible preferred stock, were converted into an equivalent number of shares of Class B common stock. Holders of Class A common stock are entitled to one vote for each share of Class A common stock held on all matters submitted to a vote of stockholders and holders of Class B common stock are entitled to ten votes for each share of Class B common stock held on all matters submitted to a vote of stockholders. Except with respect to voting, the rights of the holders of Class A and Class B common stock are identical. Shares of Class B common stock are voluntarily convertible into shares of Class A common stock at the option of the holder and are generally automatically converted into shares of the Company's Class A common stock upon sale or transfer. Shares issued in connection with exercises of stock options, vesting of restricted stock units, or shares purchased under the employee stock purchase plan are generally automatically converted into shares of the Company’s Class A common stock. Shares issued in connection with an exercise of the common stock warrants are converted into shares of the Company’s Class B common stock. Common Stock Reserved For Issuance At December 31, 2017, the Company had reserved shares of common stock for issuance as follows: December 31, 2017 (in thousands) Conversion of outstanding warrants 184 Common stock awards issued under equity incentive plan 26,608 Common stock awards available for grant under equity incentive plan 12,202 Total 38,994 Equity Incentive Plans The 2008 Equity Incentive Plan (the “2008 Plan”) became effective in February 2008. The 2008 Plan allowed for the grant of incentive stock options to our employees and any of our subsidiary corporations’ employees and for the grant of non-statutory stock options and restricted stock awards to our employees, officers, directors and consultants. Options granted under the 2008 Plan were granted at a price per share equivalent to the fair market value on the date of grant. Recipients of option grants under the 2008 Plan who possess more than 10% of the combined voting power of the Company (a “10% Shareholder”) are subject to certain limitations, and incentive stock options granted to such recipients were at a price no less than 110% of the fair market value at the date of grant. Options under the 2008 Plan generally vest over four years and have a term of 10 years. Upon the closing of the Company’s IPO, the Company’s Board of Directors adopted the 2017 Equity Incentive Plan (the “2017 Plan”). No further shares would be issued under the 2008 Plan at the time the 2017 Plan became effective. The 2017 Plan became effective in September 2017. The 2017 Plan provides for the grant of incentive stock options to our employees and for the grant of non-statutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance stock awards, performance cash awards, and other forms of equity compensation to our employees, directors and consultants. Options under the 2017 Plan generally vest over four years and have a term of 10 years. The following table summarizes the Company’s stock option activities under the 2008 Plan and 2017 Plan: Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Life (Years) Weighted Average Grant Date Fair Value Per Share Aggregate Intrinsic Value (in thousands, except price per share data) Balance, December 27, 2014 - outstanding 14,077 $ 2.01 7.2 — Granted 7,203 5.82 — $ 2.58 Exercised (797 ) 1.10 — — Forfeited and expired (633 ) 3.88 — — Balance, December 26, 2015 19,850 3.37 7.1 — Granted 4,039 6.35 — 2.71 Exercised (125 ) 3.49 — — Forfeited and expired (1,429 ) 4.54 — — Balance, December 31, 2016 22,335 3.66 6.6 — Granted 6,083 7.88 — 3.73 Exercised (963 ) 2.54 — — Forfeited and expired (1,119 ) 5.85 — — Balance, December 31, 2017 - outstanding 26,336 $ 4.59 6.4 — $ 1,242,901 Options exercisable at December 31, 2017 15,311 $ 3.00 4.6 — $ 746,939 The total intrinsic value of options exercised in the years ended December 31, 2017, 2016 and December 26, 2015 was $20.4 million, $0.4 million, and $3.9 million, respectively, and represents the difference between the fair value of the Company’s common stock at the dates of exercise and the exercise price of the options. Early Exercise of Stock Options The 2008 Plan allows employees to exercise options granted prior to vesting, if approved by the Company’s Board of Directors. The unvested shares are subject to the Company’s repurchase right at the original purchase price. The proceeds from the early exercise of stock options are initially recorded as an accrued liability and reclassified to stockholders’ equity as the Company’s repurchase right lapses. The number of unvested shares subject to repurchase that were outstanding as of December 31, 2017, 2016 and December 26, 2015 were not material. Stock-based Compensation The Company measures the cost of employee services received in exchange for an award of equity instruments based on the grant date fair value of the award. Generally, stock options granted to employees vest 25% after one year and then 1/48th monthly thereafter, and restricted stock units issued generally vest 25% after one year and then 1/16th quarterly thereafter, and have a term of ten years. The following table shows total stock-based compensation expense included in the accompanying Consolidated Statements of Operations for the years ended December 31, 2017, 2016 and December 26, 2015: Year Ended December 31, 2017 December 31, 2016 December 26, 2015 (in thousands) Cost of player revenue $ 145 $ 136 $ 90 Cost of platform revenue 81 224 54 Research and development 4,714 2,766 1,685 Sales and marketing 2,817 2,292 1,678 General and administrative 3,196 2,788 1,777 Total stock-based compensation $ 10,953 $ 8,206 $ 5,284 The fair value of options granted under the 2008 Plan and 2017 Plan is estimated on the grant date using the Black-Scholes option-valuation model. This valuation model for stock-based compensation expense requires the Company to make certain assumptions and judgments about the variables used in the calculation, including the expected term, the expected volatility of the Company’s common stock, an assumed risk-free interest rate, and expected dividends. In addition to these assumptions, the Company also estimated a forfeiture rate of unvested stock options to calculate the stock-based compensation expense prior to January 1, 2017. Beginning January 1, 2017, the Company began recognizing forfeitures as they occur with the adoption of the new guidance related to accounting for stock-based payment award transactions. The impact of the change was not material to the financial statements. Fair Value of Common Stock Prior to our IPO, the fair value of the common stock underlying our stock options was determined by our Board of Directors. The valuations of our common stock were determined in accordance with the guidelines outlined in the American Institute of Certified Public Accountants Practice Aid, Valuation of Privately-Held-Company Equity Securities Issued as Compensation. Our Board of Directors, with input from management, exercised significant judgment and considered numerous objective and subjective factors to determine the fair value of our common stock at each grant date, including but not limited to the prices, rights, preferences and privileges of our preferred stock relative to the common stock, our operating and financial performance, current business conditions and projections, our stage of development, likelihood of achieving a liquidity event for the shares of common stock underlying these stock options, such as an IPO or sale of our company, given prevailing market conditions, any adjustment necessary to recognize a lack of marketability of the common stock underlying the granted options, the market performance of comparable publicly-traded companies, the U.S. and global capital market conditions. Subsequent to our IPO, we use the market closing price for our Class A common stock as reported on The NASDAQ Global Select Market on the date of grant. The Company uses the straight-line method for expense recognition. Expected Term The Company’s expected term represents the period that the Company’s stock-based awards are expected to be outstanding and is determined based on the simplified method as described in ASC Topic 718-10-S99-1, SEC Materials SAB Topic 14, Share-Based Payment Expected Volatility The Company’s volatility factor is estimated using several comparable public company volatilities for similar option terms. Expected Dividends The Company has never paid cash dividends and has no present intention to pay cash dividends in the future, and as a result, the expected dividends are $0. Risk-Free Interest Rate The Company bases the risk-free interest rate on the implied yield currently available on U.S. Treasury zero coupon issues with a remaining term equivalent to the estimated life of the stock-based awards. Where the expected term of the Company’s stock-based awards does not correspond with the term for which an interest rate is quoted, the Company performs a straight-line interpolation to determine the rate from the available term maturities. The assumptions used to value stock-based awards granted during the years ended December 31, 2017, 2016 and December 26, 2015 are as follows: Year Ended December 31, 2017 December 31, 2016 December 26, 2015 Dividend rate — — $ — Expected term (in years) 5.3 - 6.5 5.3 - 6.5 6.1 Risk-free interest rate 1.87 - 2.25% 1.33 - 1.95% 1.39 - 1.90% Expected volatility 39 - 44% 44 - 46% 43 - 46% Fair value of common stock $2.56 - $18.46 $5.64 - $6.60 $5.64 - $7.02 As of December 31, 2017, the Company had $32.3 million of unrecognized stock compensation expense related to unvested stock options that is expected to be recognized over a weighted-average period of approximately 2.7 years. Stock Option Repricing In November 2016, the Company’s Board of Directors approved a common stock option repricing program whereby previously granted and unexercised options held by current employees with exercise prices above $5.64 per share were repriced on a one-for-one basis to $5.64 per share which represented the fair value of the Company’s common stock as of the date of the repricing. There was no other modification to the vesting schedule of the previously issued option. As a result, 5.1 million unexercised options originally granted to purchase common stock at prices ranging from $5.70 to $7.02 per share were repriced under this program. We treated the repricing as a modification of the original awards and calculated additional compensation costs for the difference between the fair value of the modified award and the fair value of the original award on the modification date. The repricing resulted in incremental stock-based compensation of $1.0 million. Expense related to vested shares of $0.1 million was expensed on the repricing date and the remaining $0.9 million related to unvested shares is being amortized over the remaining vesting period of such options. Restricted Stock Units Pursuant to the 2017 Plan, the Company issued restricted stock units to employees. Restricted stock unit activity for the year ended December 31, 2017 is as follows: Shares Weighted Average Grant Date Fair Value (in thousands, except price per share data) Balance, December 31, 2016 - outstanding — $ — Awarded 274 43.55 Released — — Forfeited (2 ) 43.55 Balance, December 31, 2017 - outstanding 272 $ 43.55 The grant-date fair value of restricted stock units granted during the year ended December 31, 2017 was $11.9 million. Total unrecognized compensation cost related to restricted stock units awarded to employees was $11.6 million, which the Company expects to recognize over 3.9 years. Common Stock Warrants In July 2017 the Company issued 0.4 million shares of Class B common stock upon exercise of 0.4 million Class B common stock warrants issued in 2009. Convertible Preferred Stock Warrants Immediately prior to the IPO, outstanding convertible preferred stock warrants were as follows: Series Number Outstanding IPO closing date Number Outstanding December 31, 2016 Issuance Date Exercise Price Original Term (in thousands, except price per share data) C-2 1,250 1,250 July 13, 2011 $ 0.64931 10 years D 250 250 October 17, 2011 2.37840 10 years D 168 168 March 12, 2012 2.37840 10 years D 63 63 April 27, 2012 2.37840 10 years E 86 86 April 27, 2012 3.48546 10 years H 409 — June 9, 2017 9.17340 10 years Total 2,226 1,817 Upon the closing of the Company’s IPO, all outstanding convertible preferred stock warrants automatically converted to Class B common stock warrants. As a result of the conversion, the Company revalued the convertible preferred stock warrants as of the completion of the IPO and reclassified the outstanding preferred stock warrant liability balance to additional paid-in capital with no further re-measurements as the Class B common stock warrants are now deemed permanent equity. After the conversion, 1.9 million Class B common stock warrants were exercised and 0.1 million shares were cancelled during the year ended December 31, 2017. Since the contracts allowed for a net settlement for Class B common stock, the Company issued 1.8 million shares of Class B common stock upon exercise. As of December 31, 2017, 0.2 million Class B common stock warrants are outstanding. Prior to the IPO, the Company valued convertible preferred stock warrants using the following assumptions in the Black-Scholes model: Year Ended December 31, 2016 December 26, 2015 Dividend rate $ — $ — Expected term (in years) 3.2 - 3.9 3.3 - 3.8 Risk-free interest rate 0.7% - 1.6% 1.1% - 1.4% Expected volatility 46.2% - 47.8% 42.0% - 46.9%

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	8. COMMITMENTS AND CONTINGENCIES Commitments The Company has operating lease agreements for office, research and development and sales and marketing space in the United States, the United Kingdom (“U.K.”), Denmark, and China, with expiration dates from May 2017 to February 2021. Rent expense for the years ended December 31, 2017, 2016 and December 26, 2015 was $6.9 million, $4.6 million and $4.2 million, respectively. Future minimum lease payments under all operating leases as of December 31, 2017, are as follows: Year Ending December 31, Operating Leases (in thousands) 2018 $ 11,683 2019 11,764 2020 10,678 2021 1,112 2022 1,090 Thereafter 2,229 Less: Sublease rental income (5,153 ) Total $ 33,403 The total approximate future minimum lease payments is primarily comprised of lease payments for two office locations. The first is for the Company’s headquarters facilities in Los Gatos, California, which expires in 2020 and has future operating lease obligations of $19.2 million. The second is for the Company’s prior headquarters facility in Saratoga, California, which expires in 2020 and has future operating lease obligations of $7.5 million. In connection with its leased facilities the Company recognized a liability for asset retirement obligations in 2015 representing the present value of estimated costs to be incurred at lease expiration. The liability for asset retirement obligations was $0.5 million and $0.3 million as of December 31, 2017 and 2016, respectively. Manufacturing Purchase Commitments The Company has various manufacturing contracts with vendors in the conduct of the normal course of its business. One major vendor has contracts that are noncancelable or have varying provisions regarding cancellation. As of December 31, 2017 and 2016, the Company had $75.2 million and $64.3 million purchase commitments for inventory, respectively. The Company records a liability for noncancelable purchase commitments in excess of its future demand forecasts. The Company recorded $0.6 million and $2.0 million for these purchase commitments in “Accrued liabilities” at December 31, 2017 and 2016, respectively. Content License Purchase Commitments The Company licenses certain content for users to access through The Roku Channel. An obligation for licensing of content is incurred at the time the Company enters into an agreement to obtain future titles and the cost of the content is known. Certain agreements include the obligation to license rights for unknown future titles, the ultimate quantity and/or fees for which are not yet determinable as of the reporting date. At December 31, 2017, the amount recorded as obligations in “Accrued liabilities” for license purchase commitments were not material. At December 31, 2017, the Company had $1.1 million of obligations that are not reflected on the financial statements as they do not yet meet the criteria for asset and liability recognition. Loss from Exit of Facilities In January 2016, the Company moved its headquarters facilities to Los Gatos, California from Saratoga, California. The Company has entered into subleases for a portion of the former headquarters and expects to sublease the remaining portion for the remainder of the lease period. In connection with the move, the Company recognized a facilities exit charge for the estimated loss on the sublease in its “Operating Expenses”. The estimated loss is comprised of the remaining fair value of lease obligations and related expenses for exited locations, as determined at the cease-use dates of those facilities, net of estimated sublease income that could be reasonably obtained in the future, and will be paid out over the remaining lease terms, which end in the year ending December 31, 2020. Projected sublease income is based on management’s estimates, which are subject to change. A summary of the Company’s exit liability activity for the year ended December 31, 2017 and 2016, is as follows: December 31, 2017 December 31, 2016 (in thousands) Beginning balance $ 2,085 $ - Change in estimated loss from exit 525 3,804 Non-cash adjustment - 1,120 Amortization of liability (1,831 ) (2,839 ) Ending balance $ 779 $ 2,085 The Company recorded $0.7 million of the above lease liability in “Accrued liabilities” and the remaining $0.1 million in “Other long-term liabilities” at December 31, 2017. Letters of Credit As of December 31, 2017 the Company had irrevocable letters of credit outstanding in the amount of $1.5 million for the benefit of a landlord related to noncancelable facilities leases. The letters of credit expire on various dates in 2018. Contingencies The Company may be involved in disputes or litigation matters that arise in the ordinary course of business. Management is not aware of any dispute that it believes would have a material adverse effect on its business, operating results, cash flows or financial condition. Indemnification Many of the Company’s agreements include certain provisions for indemnifying content publishers, licensees, contract manufacturer and suppliers if the Company’s products or services infringe a third party’s intellectual property rights. It is not possible to determine the maximum potential amount under these indemnification obligations due to the limited history of prior indemnification claims and the unique facts and circumstances involved in each agreement. To date, the Company has not incurred any material costs as a result of such obligations and have not accrued any liabilities related to such obligations in the consolidated financial statements. Player Warranties Upon issuance of a standard player warranty, the Company recognizes a liability for the obligation it assumes under the warranty. As of December 31, 2017, 2016 and December 26, 2015 the accrued warranty reserve was immaterial. The Company’s standard player warranty period ranges from 12 to 24 months from the date of player activation. Upon shipment of player to its customers, the Company estimates expenses for the cost to replace products that may be returned under warranty and accrues a liability in cost of player revenue for this amount. The determination of the Company’s warranty requirements is based on historical experience. The Company estimates and adjusts these accruals at each balance sheet date for changes in these factors. The Company offered customers separately priced optional-extended warranties through 2016. The Company defers and amortizes revenue associated with the sales of the extended warranties over the warranty period. As of December 31, 2017, 2016 and December 26, 2015, the extended warranty deferred revenue was immaterial.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	9. INCOME TAXES The components of loss before income taxes consist of the following: Year Ended December 31, 2017 December 31, 2016 December 26, 2015 (in thousands) United States $ (63,831 ) $ (42,977 ) $ (41,696 ) Foreign 637 430 1,232 Net loss before income taxes $ (63,194 ) $ (42,547 ) $ (40,464 ) The income tax expense consisted of the following: Year Ended December 31, 2017 December 31, 2016 December 26, 2015 (in thousands) Current: Federal $ — $ — $ — State 89 50 71 Foreign 674 160 76 763 210 147 Deferred: Federal — — — State — — — Foreign (448 ) 1 — Total $ 315 $ 211 $ 147 The following is a reconciliation of the statutory federal income tax rate to the Company’s effective tax rate: Year Ended December 31, 2017 December 31, 2016 December 26, 2015 U.S. federal income tax at statutory rate 34.0 % 34.0 % 34.0 % U.S. state and local income taxes (0.2 ) (0.1 ) (0.2 ) Change in valuation allowance 19.0 (36.9 ) (33.7 ) Federal research and development tax credit 5.2 4.8 3.9 Convertible preferred stock warrants (21.7 ) 0.7 (1.5 ) Stock-based compensation 1.2 (2.5 ) (1.7 ) Permanent items (1.1 ) (0.2 ) (1.1 ) Foreign rate differential 0.2 — 0.4 Tax rate change (36.4 ) — — Other (0.7 ) (0.2 ) (0.5 ) Effective tax rate (0.5 )% (0.4 )% (0.4 )% Significant components of the Company’s deferred income tax assets and liabilities consist of the following: December 31, 2017 December 31, 2016 (in thousands) Deferred tax assets: Net operating loss carryforwards $ 34,843 $ 46,954 Reserves and accruals 13,577 15,575 Research and development credits 15,475 10,555 Depreciation and amortization 288 1,568 Stock-based compensation 4,098 4,068 Total deferred tax assets 68,281 78,720 Valuation allowance (68,219 ) (78,695 ) Net deferred tax assets $ 62 $ 25 A valuation allowance is provided when it is more likely than not that some portion of the deferred tax assets will not be realized through future operations. As a result of the Company’s analysis of all available objective evidence, both positive and negative, as of December 31, 2017, management believes it is more likely than not that the deferred tax assets will not be fully realizable. Accordingly, the Company has provided a full valuation allowance against its deferred tax assets with the exception of deferred tax assets related to foreign entities in the U.K., China and Denmark. For federal and state income tax reporting purposes, respective net operating loss carryforwards of $135.2 million and $104.1 million are available to reduce future taxable income, if any. These net operating loss carryforwards will begin to expire in 2028 for federal and state income tax purposes. During the year ended December 31, 2017 the Company adopted the requirements of ASU 2016-09, Compensation—Stock Compensation (Topic 718): Improvements to Employee Share -Based Payment Accounting, As of December 31, 2017, the Company has research and development tax credit carryforwards of $13.4 million and $9.1 million for federal and state income tax purposes, respectively. If not utilized, the federal carryforwards will begin to expire in 2028. The state tax credits can be carried forward indefinitely. The Internal Revenue Code of 1986, as amended (the “Code”), contains provisions that may limit the net operating loss and credit carryforwards available for use in any given period upon the occurrence of certain events, including a statutorily defined significant change in ownership. Utilization of the net operating loss and tax credit carryforwards is subject to an annual limitation due to an ownership change, as defined by section 382 of the Code. The Company completed a recent study to assess whether any section 382 ownership change has occurred since the Company’s formation. Based on the study, the Company had a section 382 ownership change on December 18, 2009 and tax attributes generated by the Company through the ownership change date are subject to the limitation. The Company has determined that there is no additional ownership change since December 18, 2009. The total amount of unrecognized tax benefits as of December 31, 2017 is $5.8 million which is fully composed of research and development credits. A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows: December 31, 2017 December 31, 2016 (in thousands) Unrecognized tax benefits at beginning of year $ 4,368 $ 2,917 Gross increase for tax positions of current years 1,475 1,246 Gross increase for tax positions of prior year — 205 Gross decrease for tax positions of prior years — — Unrecognized tax benefits balance at end of year $ 5,843 $ 4,368 The Company recognizes interest and penalties related to unrecognized tax benefits as a component of its income tax expense. As of December 31, 2017, there were no accrued interest and penalties related to uncertain tax positions. None of the Company’s unrecognized tax benefit, if recognized, would affect its effective tax rate. The Company does not believe that the amount of unrecognized tax benefits will change significantly in the next 12 months. The Company files income tax returns in the U.S. federal jurisdiction and various state jurisdictions. In the normal course of business, the Company is subject to examination by taxing authorities. These audits include questioning the timing and amount of deductions; the nexus of income among various tax jurisdictions; and compliance with federal, state, and local tax laws. The Company is not currently under audit by the Internal Revenue Service or other similar state and local authorities. All tax years remain open to examination by major taxing jurisdictions to which the Company is subject. On December 22, 2017, the U.S. government enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act (the "Tax Act"). The Tax Act reduces the US federal corporate tax rate from 35% to 21%, imposes a one-time repatriation tax, and numerous other provisions transitioning to a territorial system. The SEC staff issued Staff Accounting Bulletin No. 118 (“SAB 118”), which provides guidance on accounting for the tax effects of the Tax Act. SAB 118 provides a measurement period that should not extend beyond one year from the Tax Act enactment date for companies to complete the accounting under ASC 740. In accordance with SAB 118, a company must reflect the income tax effects of those aspects of the Act for which the accounting under ASC 740 is complete. To the extent that a company’s accounting for certain income tax effects of the Tax Act is incomplete but it is able to determine a reasonable estimate, it must record a provisional estimate in the financial statements. If a company cannot determine a provisional estimate to be included in the financial statements, it should continue to apply ASC 740 on the basis of the provisions of the tax laws that were in effect immediately before the enactment of the Tax Act. Based on provisions of the Tax Act, the Company remeasured the deferred tax assets and liabilities based on the rates at which they are expected to reverse in the future, which is generally 21%. The estimated amount of the re-measurement of our deferred tax balance was $23.0 million. However, as the Company recognizes a valuation allowance on deferred tax assets if it is more likely than not that the assets will not be realized in future years there is no impact to effective tax rate, as any change to deferred taxes would be offset by valuation allowances. The one-time repatriation tax is based on the Company's post-1986 earnings and profits (E&P) that were previously deferred from US income taxes. The one-time repatriation tax did not result in additional tax liability for the Company as the Company has sufficient net operating loss to offset the estimated foreign earnings. As a result of the one-time repatriation tax, the Company has not provided for any foreign withholding tax for any undistributed earnings of its foreign subsidiaries as of December 31, 2017. The Company has not yet made a determination of indefinite reinvestment assertion in light of the Tax Act and considers the conclusion to be incomplete under guidance issued by the SEC. The Company expects to reach a final determination within the measurement period in accordance with SAB 118. The changes included in the Tax Act are broad and complex. The final transition impacts of the Tax Act may differ from the above estimate, possibly materially, due to, among other things, changes in interpretations of the Tax Act, any legislative action to address questions that arise because of the Tax Act, any changes in accounting standards for income taxes or related interpretations in response to the Tax Act, or any updates or changes to estimates the Company has utilized to calculate the transition impacts, including impacts from changes to current year earnings estimates and foreign exchange rates of foreign subsidiaries. The Securities and Exchange Commission has issued rules that would allow for a measurement period of up to one year after the enactment date of the Tax Act to finalize the recording of the related tax impacts. The Company currently anticipates finalizing and recording any resulting adjustments by the year ending December 31, 2018. The Act creates a new requirement that global intangible low-taxed income (GILTI) earned by controlled foreign corporations (CFCs) must be included currently in the gross income of the CFCs’ U.S. shareholder. Because of the complexity of the new GILTI tax rules, we are continuing to evaluate this provision of the Act and the application of ASC 740. Under U.S. GAAP, we are allowed to make an accounting policy choice of either (1) treating taxes due on future U.S. inclusions in taxable income related to GILTI as a current-period expense when incurred (the “period cost method”) or (2) factoring such amounts into a company’s measurement of its deferred taxes (the “deferred method”). Our selection of an accounting policy with respect to the new GILTI tax rules will depend, in part, on analyzing our global income to determine whether we expect to have future U.S. inclusions in taxable income related to GILTI and, if so, what the impact is expected to be. We have not yet made any adjustments related to potential GILTI tax in our financial statements and have not made a policy decision regarding whether to record deferred taxes on GILTI.

Related-Party Transactions

Related-Party Transactions	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Related-Party Transactions	10. RELATED-PARTY TRANSACTIONS The Company has agreements with one of the Company’s strategic investors. In the years ended December 31, 2017, 2016 and December 26, 2015 the Company recorded $0.6 million, $0.7 million and $0.5 million of revenue from sales to this investor. The Company had receivable balances of $0.5 million and $0.1 million related to these sales at December 31, 2017 and 2016, respectively. In addition, a member of the Company’s Board of Directors is a senior vice president at an operating unit of one of the strategic investors. The Company recorded expenses of $0.4 million in operating expenses from transactions with this investor for the year ended December 31, 2017. There were no transactions with this investor for the year ended December 31, 2016.

Retirement Plans

Retirement Plans	12 Months Ended
	Dec. 31, 2017
Compensation And Retirement Disclosure [Abstract]
Retirement Plans	11. RETIREMENT PLANS The Company maintains a 401(k) tax deferred saving plan (the “Savings Plan”) for the benefit of qualified employees. Qualified employees may elect to make contributions to the Savings Plan on a biweekly basis, subject to certain limitations. The Company may make contributions to the Savings Plan at the discretion of the Board of Directors. No contributions were made for the years ended December 31, 2017, 2016 and December 26, 2015. In 2014, the Company established a defined contribution plan in the U.K. for its U.K.-based employees. The Company contributed $0.3 million, $0.2 million and $0.2 million to the plan for years ended December 31, 2017, 2016, and December 26, 2015, respectively.

Net Loss Per Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Net Loss Per Share	12. NET LOSS PER SHARE The Company calculates its basic and diluted net loss per share allocable to common stockholders in conformity with the two-class method required for companies with participating securities. In computing diluted net loss allocable to common stockholders, undistributed earnings are re-allocated to reflect the potential impact of dilutive securities. The Company’s basic net loss per share allocable to common stockholders is calculated by dividing the net loss allocable to common stockholders by the weighted-average number of shares of common stock outstanding for the period. For purposes of the calculation of diluted net loss per share allocable to common stockholders, convertible preferred stock, unvested shares of common stock issued upon the early exercise of stock options, convertible preferred stock warrants, options to purchase common stock and common stock warrants are considered common stock equivalents but have been excluded from the calculation of diluted net loss per share allocable to common stockholders as their effect is antidilutive. Basic and diluted net loss per share of common stock allocable to common stockholders is calculated by dividing the net loss allocable to common stockholders by the weighted-average number of shares of common stock outstanding during the period, less shares subject to repurchase, and excludes any dilutive effects of employee stock-based awards and warrants. Because the Company has reported a net loss for the years ended December 31, 2017, 2016 and December 26, 2015, diluted net loss per common share is the same as the basic net loss per share for those years. The Company considers all series of its convertible preferred stock to be participating securities as they are entitled to receive noncumulative dividends prior and in preference to any dividends on shares of common stock. Due to the Company’s net losses, there is no impact on the loss per share calculation in applying the two-class method since the participating securities have no legal obligation to share in any losses. The table presents the calculation of basic and diluted net loss per share as follows: Year Ended December 31, 2017 December 31, 2016 December 26, 2015 (in thousands, except per share data) Numerator: Net loss allocable to common stockholders $ (63,509 ) $ (42,758 ) $ (40,611 ) Denominator: Weighted-average shares used in computing net loss per share, basic and diluted 28,308 4,746 4,030 Net loss per share, basic and diluted $ (2.24 ) $ (9.01 ) $ (10.08 ) The potential common shares that were excluded from the calculation of diluted net loss per share because their effect would have been antidilutive for the periods presented are as follows: Year Ended December 31, 2017 December 31, 2016 December 26, 2015 (in thousands) Equity awards to purchase common stock 26,608 22,335 19,850 Unvested shares of common stock issued upon early exercise of stock options 57 3 12 Warrants to purchase common stock 184 375 542 Warrants to purchase convertible preferred stock - 1,817 1,817 Convertible preferred stock - 80,844 80,844 Total 26,849 105,374 103,065

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Segment Information	13. SEGMENT INFORMATION An operating segment is defined as a component of an entity for which discrete financial information is available that is evaluated regularly by the chief operating decision maker (“CODM”) for purposes of allocating resources and evaluating financial performance. The Company uses the management approach to determine the segment financial information that should be disaggregated and presented separately in the Company’s notes to its consolidated financial statements. The management approach is based on the manner by which management has organized the segments within the Company for making operating decisions, allocating resources, and assessing performance. The Company reports its financial results consistent with the manner in which financial information is viewed by management for decision-making purposes. The Company does not manage operating expenses such as research and development, sales and marketing and general and administrative expenses at the segment level. The Company’s CODM is its Chief Executive Officer, and the CODM evaluates performance and makes decisions about allocating resources to its operating segments based on financial information presented on a consolidated basis and on revenue and gross profit for each operating segment. In the second quarter of 2017 the Company changed the operating segments to combine one of the previous operating segments with two existing segments to reflect how the CODM evaluates performance and allocates resources. This change did not result in a change to the reportable segments. The Company is organized into two reportable segments as follows: Player Consists primarily of net sales of streaming media players and accessories through retailers and distributors, as well as directly to customers through the Company’s website. Platform Consists primarily of fees received from advertisers and content publishers, and from licensing the Company’s technology and proprietary operating system with TV brands and service operators. Platform revenue primarily includes fees earned from the sale of digital advertising and revenue share from new or recurring user subscriptions activated through the Company’s platform and revenue share from user purchases of content publishers’ media through its platform. The Company also earns revenue from the sale of branded channel buttons on player and TV remote controls. The Company does not allocate property and equipment or any other assets or capital expenditures to reportable segments. Operating expenses are not managed at the segment level. The Company evaluates the performance of its reportable segments based on the financial measures, including segment gross profit, which are regularly reviewed by the CODM and provide insight into the individual segments and their ability to contribute to Company’s operating results. Customers accounting for 10% or more of segment revenue, net, were as follows: Year Ended December 31, 2017 December 31, 2016 December 26, 2015 Player segment revenue Customer A 15 % 18 % 19 % Customer B 12 11 12 Customer C 34 32 26 Platform segment revenue Customer B * % 15 % 31 % Customer F * * 11 Customer E 13 % 10 * * Less than 10% Revenue in international markets was less than 10% in each of the periods presented. Substantially all Company assets were held in the United States and were attributable to the operations in the United States as of December 31, 2017 and 2016.

Quarterly Financial Data (Unaud

Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data (Unaudited)	14. QUARTERLY FINANCIAL DATA (Unaudited) The following table summarizes the Company’s information on total revenue, gross profit, net income (loss) and earnings per share by quarter for the years ended December 31, 2017 and 2016. This data was derived from the Company’s unaudited consolidated financial statements. Three Months Ended Dec 31, 2017 Sep 30, 2017 Jun 30, 2017 Mar 31, 2017 Dec 31, 2016 Oct 1, 2016 Jul 2, 2016 Apr 2, 2016 (in thousands, except per share amounts) Total Revenue $ 188,261 $ 124,782 $ 99,627 $ 100,093 $ 147,340 $ 89,053 $ 83,809 $ 78,447 Gross Profit 73,461 49,895 37,637 38,840 44,663 26,050 25,076 25,256 Net income (loss) 6,941 (46,235 ) (15,513 ) (8,702 ) 3,227 (12,743 ) (14,109 ) (19,133 ) Net income attributable to participating securities - - - - 3,227 - - - Net income (loss) attributable to common stockholders 6,941 (46,235 ) (15,513 ) (8,702 ) - (12,743 ) (14,109 ) (19,133 ) Basic net income (loss) per share attributable to common stockholders 0.07 (8.79 ) (3.18 ) (1.79 ) - (2.66 ) (2.98 ) (4.10 ) Diluted net income (loss) per share attributable to common stockholders 0.06 (8.79 ) (3.18 ) (1.79 ) - (2.66 ) (2.98 ) (4.10 )

Summary of Significant Accoun23

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation The consolidated financial statements, which include the accounts of Roku, Inc. and its wholly-owned subsidiaries, have been prepared in conformity with accounting principles generally accepted in the United States (“U.S. GAAP”). All intercompany accounts and transactions have been eliminated in consolidation.
Fiscal Year	Fiscal Year Prior to 2017, the Company’s fiscal year was the 52- or 53-week period that ended on the last Saturday of December. The fiscal years 2015 and 2016 ended on December 26, 2015 and December 31, 2016, respectively. In 2017, the Company changed the fiscal year-end to match the calendar year-end. Fiscal year 2015 spanned 52 weeks and fiscal year 2016 spanned 53 weeks.
Use of Estimates	Use of Estimates The preparation of the Company’s consolidated financial statements in accordance with U.S. GAAP requires management to make certain estimates, judgments, and assumptions that affect the reported amounts of assets and liabilities and related disclosures at the date of the financial statements, as well as the reported amounts of revenue and expenses during the periods presented. Significant items subject to such estimates include revenue recognition for multiple element arrangements, determination of revenue reporting as net versus gross, sales return reserves, customer incentive programs, inventory valuation, the valuation of deferred income tax assets, the recognition and disclosure of contingent liabilities, stock-based compensation and the fair value of assets and liabilities acquired in business combinations. The Company bases its estimates on historical experience and on various other assumptions that the Company believes to be reasonable under the circumstances. Actual results may differ from the Company’s estimates.
Comprehensive Loss	Comprehensive Loss Comprehensive loss is equal to the net loss for all periods presented. Therefore, the consolidated statements of comprehensive loss have been omitted from the consolidated financial statements.
Foreign Currency	Foreign Currency The functional currency of the Company’s foreign subsidiaries is the U.S. dollar. Monetary assets and liabilities of these subsidiaries are remeasured into U.S. dollars from the local currency at rates in effect at period-end and nonmonetary assets and liabilities are remeasured at historical rates. Revenues and expenses are remeasured at average exchange rates in effect during each period. Foreign currency gains or losses from re-measurement and transaction gains or losses are recorded as other income (expense), net in the consolidated statements of operations. During the years ended December 31, 2017 and 2016, the Company recorded foreign currency gain of $0.1 million and foreign currency loss of $0.4 million, respectively.
Concentrations	Concentrations Financial instruments, which potentially subject the Company to concentrations of credit risk, consist principally of cash and accounts receivable. As of December 31, 2017 and 2016, 95% and 94% of the Company’s cash balances were managed by one financial institution. Accounts receivable are typically unsecured and are derived from revenue earned from customers. They are stated at invoice value less estimated allowances for returns, customer incentives and doubtful accounts. The Company performs ongoing credit evaluations of its customers and maintains allowances for potential credit losses. Customers accounting for 10% or more of the Company’s net revenue were as follows Year Ended December 31, 2017 December 31, 2016 December 26, 2015 Customer A * % 13 % 16 % Customer B 10 12 15 Customer C 20 24 23 Customer E 10 * * Customers accounting for 10% or more of the Company’s accounts receivable were as follows: December 31, 2017 December 31, 2016 Customer A * % 12 % Customer B * 11 Customer C * 17 Customer D 16 17 * Less than 10%
Business Combinations	Business Combinations We determine the fair value of the assets acquired and liabilities assumed based on their estimated fair values as of the date of acquisition. Goodwill is measured at the acquisition Any contingent consideration payable is recognized at fair value at the acquisition date. Liability-classified contingent consideration is remeasured each reporting period with changes in fair value recognized in earnings until the contingent consideration is settled. When we issue payments or grants of equity to selling shareholders in connection with an acquisition, we evaluate whether the payments or awards are compensatory. This evaluation includes whether cash payments or stock award vesting is contingent on the continued employment of the selling stockholder beyond the acquisition date. If continued employment is required for the cash to be paid or stock awards to vest, the award is treated as compensation for post-acquisition services and is recognized as compensation expense. Acquisition related costs incurred in connection with a business combination, other than those associated with the issuance of debt or equity securities, are expensed as incurred.
Goodwill, Purchased Intangible Assets and Impairment Assessment	Goodwill, Purchased Intangible Assets and Impairment Assessment Goodwill represents the excess of the purchase price over the fair value of the assets acquired and liabilities assumed, if any, in a business combination. The Company reviews its goodwill for impairment annually, as of the beginning of the fourth quarter, and whenever events or changes in circumstances indicate that impairment may exist. The Company did not recognize any impairment of goodwill in the year ended December 31, 2017. Purchased intangible assets consist primarily of developed technology. Purchased intangible assets are recorded at fair value on the date of acquisition and amortized over their estimated useful lives following the pattern in which the economic benefits of the assets will be consumed, generally straight-line. The carrying amounts of our purchased intangible assets are periodically reviewed for impairment whenever events or changes in circumstances indicate that the carrying value of these assets may not be recoverable or that the useful life is shorter than originally estimated.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company’s long-lived assets include property and equipment and other noncurrent assets and are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recovered. Recoverability of assets is measured first by comparing their carrying amounts to their future undiscounted net cash flows. If such assets are considered to be impaired, the impairment to be recognized equals the amount by which the carrying value of the asset exceeds its fair market value. No impairment was recorded during the year ended December 31, 2017. The Company recorded an impairment of $0.3 million for obsolete internal-use software during the year ended December 31, 2016.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The Company defines fair value as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The Company applies fair value accounting for all assets and liabilities that are recognized or disclosed at fair value in the consolidated financial statements on a recurring basis. The carrying amounts reported in the consolidated financial statements for cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities approximate their fair values due to their short-term nature.
Inventories	Inventories The Company’s inventories consist primarily of finished goods and are stated at the lower of cost or market with cost determined on a first-in, first-out basis and market based on net realizable value. If the cost of the inventories exceeds their net realizable value, provisions are made currently for the difference between the cost and the market value. The Company evaluates inventory levels and purchase commitments for excess and obsolete products, based on management’s assessment of future demand and market conditions.
Property and Equipment	Property and Equipment Property and equipment are recorded at cost and depreciated using the straight-line method over their estimated useful lives of the assets, generally ranging between eighteen months and five years. Leasehold improvements are amortized over the shorter of the lease term or their estimated useful lives, which is generally five years.
Website and Internal-Use Software	Website and Internal-Use Software The Company capitalizes costs to develop its website and internal-use software. The Company expenses all costs that relate to the planning and post-implementation phases of development as incurred. The Company capitalizes subsequent costs when preliminary efforts are successfully completed, management has authorized and committed project funding, and it is probable that the project will be completed and will be used as intended. Costs incurred for enhancements that are expected to result in additional material functionality are capitalized. During the years ended December 31, 2017, 2016 and December 26, 2015, the Company capitalized website and internal-use software development costs of $2.6 million, $1.8 million and $0.7 million, respectively. Capitalized costs are amortized using the straight-line method over an estimated useful life of the asset, which is generally two years, beginning when the asset is ready for its intended use. During the years ended December 31, 2017, 2016 and December 26, 2015, the Company amortized expenses of $1.1 million, $0.7 million and $0.3 million, respectively.
Streaming Content	Streaming Content The Company licenses certain content for users to access through The Roku Channel. The content licenses can be for a fixed fee and/or advertising revenue share with specific windows of content availability. The Company capitalizes the content license fees and records a corresponding liability when the license period begins, the cost of the content is known and the content is accepted and available for streaming. The Company amortizes the content assets into “Cost of Revenue, Platform” over the contractual window of availability. At December 31, license fees included in “Prepaid expenses and other current assets” are not material.
Revenue Recognition	Revenue Recognition The Company derives revenue primarily from sales of its players and platform services. Revenue is recognized when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the price is fixed or determinable, and collectability is reasonably assured. Multiple Element Arrangements —The Company commonly enters into multiple-element arrangements. In such arrangements, the Company will combine arrangement deliverables into units of accounting and allocate the total arrangement consideration to the different units of accounting based on a relative selling price hierarchy. To determine the relative selling price of each element, the Company uses vendor-specific objective evidence of fair value (“VSOE”), if available, third party evidence (“TPE”), if VSOE is not available, or best estimated selling price (“BESP”), if neither VSOE nor TPE are available. The objective of BESP is to determine the price at which the Company would transact a sale if the product or service were available on a standalone basis. The Company establishes BESP considering multiple factors including, but not limited to, historical prices of products sold on a stand-alone basis, cost and gross margin objectives, competitive pricing practices and customer and market specific considerations. Revenue is recognized for each unit of accounting provided that all revenue recognition criteria have been met. Players —The Company sells the majority of its players through consumer retail distribution channels, including brick and mortar and online retailers, and through the Company’s website. For sales through consumer retail distribution channels, revenue recognition occurs when title and risk of loss have transferred to the customer which usually occurs upon shipment to the customers or receipt of the products by the customer depending on shipping terms. The Company establishes allowances for expected product returns and these allowances are recorded as a direct reduction to revenue. Return allowances are based on the Company’s historical experience. Certain payments to retailers and distributors such as market development funds, store promotions and price protection are recorded as a reduction of revenue. The Company reduces revenue at the later of the date at which the related player revenue is recognized or the date on which the program is offered. On occasion, these allowances cannot be reasonably and reliably estimated. Player revenue is then recognized at the time the players sell through to the end customer. The Company’s player sales include two units of accounting: hardware, which includes embedded software, and unspecified upgrades or enhancements on a when-and-if available basis. The Company has determined that its hardware and embedded software be considered as one single unit of accounting, because the hardware and software individually do not have standalone value and are not sold separately. The Company initially records the relative selling price of the unspecified upgrades or enhancements on a when-and-if-available basis as deferred revenue, and then recognizes the deferred revenue into player, net revenue ratably on a straight-line basis over the estimated economic life of the associated players. Shipping charges billed to customers are included in player revenue and the related shipping costs are included in cost of player revenue. Revenue is recorded net of taxes collected or accrued. Sales taxes are recorded as current liabilities until remitted to the relevant government authority. Platform —The Company earns platform revenue from fees received from advertisers and content publishers and licensing its technology and proprietary operating system to service operators and TV brands. Platform revenue primarily includes fees earned or derived from the sale of digital advertising, revenue sharing with content publishers for new or recurring user subscriptions activated through the Company’s platform and revenue share from user purchases of content publishers’ media through its platform. The Company also earns revenue from the sale of branded channel buttons on remote controls. Licensing revenues from service operators are mostly generated from unit activation or flat fees and ongoing maintenance fees. Licensing revenues from TV brands are generated on a flat fee basis or from per unit licensing fees earned. Digital advertising includes video and display ads that are served on the Company’s platform. Digital advertising revenue consists of video and display advertising commonly sold on a cost per thousand impression basis. Advertising revenue arrangements are evidenced by a fully executed insertion order. Revenue is recognized in the period the impressions and promotional media are delivered. Fees derived from the Company’s billing services supporting new or recurring user subscriptions activated through its platform and from purchases of content publishers’ media are recognized as transacted at the net amount retained by the Company, generally equal to a fixed percentage of the price charged by the content provider or a contractual flat fee. When the content publisher is responsible for user billing, the Company recognizes revenue from its share of the fees on an as reported basis, in arrears, on a monthly or quarterly basis. The Company also earns fees through the sale of branded channel buttons on remote controls. These branded buttons provide one-touch, direct access to the providers’ content on the Company’s platform. The Company typically receives a fixed fee per button unit, and revenue is recognized as remote controls are shipped by the Company or reported as shipped by TV brands. Revenues earned from service operators and TV brands in the licensing of the Company’s technology and proprietary operating system are accounted for under software revenue recognition guidance. The Company has been unable to establish VSOE for any component of these licensing arrangements and therefore these arrangements are accounted for as a single unit of accounting and revenue over the term of the relationship. Arrangements with service operators are generally comprised of a license for the technology and proprietary operating system, unspecified upgrades or enhancements, hosting of a branded channel store, and engineering and support services. Arrangements with TV brands commonly include a license to the technology and proprietary operating system over a specified term including updates and upgrades.
Deferred Revenue and Deferred Cost of Revenue	Deferred Revenue and Deferred Cost of Revenue The Company’s deferred revenue reflect fees received from licensing and service arrangements, including advertising, that will be recognized as revenue over time or as services are rendered. Deferred revenue balances consist of the amount of player sales allocated to unspecified upgrades or enhancements on a when-and-if available basis, licensing and services fees from service operators and TV brands, and payments from advertisers and content publishers. Deferred cost of revenue consists of amounts associated with related deferred revenues and is recognized as cost of revenue in the same manner as its respective deferred revenue. Deferred revenue and the associated deferred cost of revenue expected to be realized within one year are classified as current liabilities and current assets, respectively, and the remaining are recorded as noncurrent liabilities and noncurrent assets, respectively.
Warranty Costs	Warranty Costs The Company generally provides for the estimated cost of hardware and software warranties at the time the related revenue is recognized. The Company assesses the adequacy of its preexisting warranty liabilities and adjusts the amounts as necessary based on actual experience and changes in future estimates.
Advertising Costs	Advertising Costs Advertising costs are expensed when incurred and are included in sales and marketing expense in the consolidated statements of operations. The Company incurred advertising costs of $3.4 million, $3.9 million and $4.1 million for the years December 31, 2017, 2016 and December 26, 2015 respectively.
Stock-Based Compensation	Stock-Based Compensation The Company measures compensation expense for all stock-based awards, including stock options and restricted stock units granted to employees, based on the estimated fair value on the date of grant. The fair value of each stock option granted is estimated using Black-Scholes option-pricing model. Stock-based compensation is recognized on a straight-line basis over the requisite vesting period. For the years ended December 31, 2016, and December 26, 2015 the stock-based compensation was recorded net of estimated forfeitures using a forfeiture rate based on an analysis of the Company’s actual historical forfeitures. The Company adopted new guidance effective January 1, 2017 to recognize forfeitures as they occur. The Company accounts for stock options issued to nonemployees based on the fair value of the awards determined using the Black-Scholes option-pricing model. The fair value of stock options granted to nonemployees is remeasured as the stock options vest, and the resulting change in fair value, if any, is recognized in the Company’s consolidated statements of operations during the period the related services are rendered, generally four years. The Company accounts for restricted stock units issued to employees based on the grant date fair value which is determined based on the closing market price of the Class A common stock on the date of grant. The expense is recognized in the Company’s consolidated statement of operations on a straight-line basis over the requisite vesting period.
Income Taxes	Income Taxes The Company accounts for income taxes using an asset and liability approach. Deferred tax assets and liabilities are determined based on the difference between the consolidated financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to affect taxable income. Valuation allowances are established when necessary to reduce deferred tax assets to the amounts that are more likely than not to be realized.
Net Loss per Share	Net Loss per Share Since the Company was in a loss position for all periods presented, basic net loss per share is the same as diluted net loss per share for all periods as the inclusion of all potential common shares outstanding and potentially dilutive securities would have been anti-dilutive.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In January 2017, the FASB issued ASU 2017-04, Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment, In January 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business, In October 2016, the FASB issued ASU 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force), In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), In January 2016, the FASB issued ASU 2016-01, Financial Instruments—Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities, In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606), The Company is currently in the process of finalizing the impact of the new standard on its accounting policies, processes and system requirements. Furthermore, the Company has made and will continue to make investments in systems to enable timely and accurate reporting under the new standard. The Company expects that the adjustment from the adoption will result in a decrease to the accumulated deficit in the range of $32.0 million to $42.0 million. The Company believes that the new standard will impact accounting for revenue arrangements as follows: • Revenue from the licensing of the Company’s technology and proprietary operating system to service operators and TV brands, will be recognized earlier and could result in greater variability in revenue recognition; • Revenue resulting from the variable consideration (e.g. revenue share from user subscriptions and media purchases through the platform or sale of branded channel buttons on its remote controls) outlined in content publisher arrangements is estimated and allocated for the entire contract period and then recognized based on the percentage of completion across various performance obligations; and • Expanded disclosures. The Company expects revenue recognition related to players and advertising to remain relatively unchanged under the new guidance.

Summary of Significant Accoun24

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
Net Revenue
Schedules of Customer Concentration by Risk Factor	Customers accounting for 10% or more of the Company’s net revenue were as follows Year Ended December 31, 2017 December 31, 2016 December 26, 2015 Customer A * % 13 % 16 % Customer B 10 12 15 Customer C 20 24 23 Customer E 10 * *
Accounts Receivable
Schedules of Customer Concentration by Risk Factor	Customers accounting for 10% or more of the Company’s accounts receivable were as follows: December 31, 2017 December 31, 2016 Customer A * % 12 % Customer B * 11 Customer C * 17 Customer D 16 17 * Less than 10%

Balance Sheet Components (Table

Balance Sheet Components (Tables)	12 Months Ended
	Dec. 31, 2017
Balance Sheet Related Disclosures [Abstract]
Schedule of Accounts Receivable, Net	Accounts receivable, net consisted of the following: December 31, 2017 December 31, 2016 (in thousands) Gross accounts receivable $ 138,292 $ 95,686 Allowance for sales returns (6,907 ) (6,916 ) Allowance for sales incentives (10,442 ) (8,503 ) Other allowances (390 ) (794 ) Total allowances (17,739 ) (16,213 ) Total Accounts Receivable—net $ 120,553 $ 79,473
Schedule of Allowance for Sales Returns	Allowance for sales returns consist of the following activities: December 31, 2017 December 31, 2016 (in thousands) Beginning balance $ (6,916 ) $ (9,514 ) Charged to revenue (19,089 ) (20,810 ) Utilization of sales return reserve 19,098 23,408 Ending balance $ (6,907 ) $ (6,916 )
Schedule of Allowance for Sales Incentives	Allowance for sales incentive consisted of the following activities: December 31, 2017 December 31, 2016 (in thousands) Beginning balance $ (8,503 ) $ (7,642 ) Charged to revenue (44,264 ) (36,626 ) Utilization of sales incentive reserve 42,325 35,765 Ending balance $ (10,442 ) $ (8,503 )
Schedule of Property and Equipment, Net	Property and equipment, net consisted of the following: December 31, 2017 December 31, 2016 (in thousands) Computers and equipment $ 11,631 $ 8,787 Leasehold improvements 8,437 4,201 Website and internal-use software 5,461 2,902 Office equipment and furniture 1,987 1,452 Total property and equipment 27,516 17,342 Accumulated depreciation and amortization (12,780 ) (7,814 ) Property and Equipment, net $ 14,736 $ 9,528
Schedule of Accrued Liabilities	Accrued liabilities consisted of the following: December 31, 2017 December 31, 2016 (in thousands) Accrued royalty expense $ 17,165 $ 14,940 Accrued inventory 2,382 4,274 Accrued payroll and related expenses 8,699 5,342 Accrued cost of revenue 12,210 7,264 Accrued payments to content publishers 24,037 8,554 Sales tax and tax related liabilities 751 769 Other accrued expenses 7,100 5,013 Total Accrued Liabilities $ 72,344 $ 46,156
Schedule of Deferred Revenue	Deferred revenue consisted of the following: December 31, 2017 December 31, 2016 (in thousands) Player, current $ 15,479 $ 13,611 Platform, current 19,022 10,341 Total deferred revenue, current 34,501 23,952 Player, non-current 5,837 5,215 Platform, non-current 42,674 23,869 Total deferred revenue, non-current 48,511 29,084 Total Deferred Revenue $ 83,012 $ 53,036

Fair Value Disclosure (Tables)

Fair Value Disclosure (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Summary of Reconciliation of the Preferred Stock Warrant Liability Measured and Recorded at Fair Value on a Recurring Basis Using Significant Unobservable Inputs	A reconciliation of the preferred stock warrant liability measured and recorded at fair value on a recurring basis using significant unobservable inputs is as follows: Year Ended December 31, 2017 December 31, 2016 December 26, 2015 (in thousands) Convertible preferred stock warrant liability — beginning balance $ 9,990 $ 10,878 $ 10,787 Fair value of new warrants issued 2,032 — — Change in fair value* 40,333 (888 ) 1,768 Reclassification to preferred stock upon exercise — — (1,677 ) Reclassification to APIC upon conversion to common warrants (52,355 ) — — Convertible preferred stock warrant liability — ending balance $ — $ 9,990 $ 10,878 * Recognized in the consolidated statements of operations within other expense—net. Assets and liabilities that are measured at fair value on a non-recurring basis Non-financial assets such as goodwill, intangible assets, and property, plant, and equipment are evaluated for impairment and adjusted to fair value using Level 3 inputs, only when impairment is recognized. There were no indicators of impairment that required a fair value analysis during the years ended December 31, 2017 and 2016.

Stockholders' Equity (Deficit)

Stockholders' Equity (Deficit) (Tables)	12 Months Ended
	Dec. 31, 2017
Schedule of Convertible Preferred Stock	As of December 31, 2016 convertible preferred stock consisted of the following: December 31, 2016 Series Price Shares Authorized Shares Outstanding Liquidation Preference (in thousands, except price per share data) A $ 0.36312 23,020 23,020 $ 8,359 B 0.93808 6,396 6,396 6,000 C-1 0.54109 9,240 9,240 5,000 C-2 0.64931 8,950 7,700 5,000 D 2.37840 4,686 4,205 10,000 E 4.35679 11,161 11,075 48,250 F 5.43396 11,042 11,042 60,000 G 7.79730 3,206 3,206 25,000 H 9.17340 6,667 4,960 45,500 Total 84,368 80,844 $ 213,109
Schedule of Reserved Shares of Common Stock for Issuance	At December 31, 2017, the Company had reserved shares of common stock for issuance as follows: December 31, 2017 (in thousands) Conversion of outstanding warrants 184 Common stock awards issued under equity incentive plan 26,608 Common stock awards available for grant under equity incentive plan 12,202 Total 38,994
Schedule of Activity Under Equity Incentive Plan	The following table summarizes the Company’s stock option activities under the 2008 Plan and 2017 Plan: Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Life (Years) Weighted Average Grant Date Fair Value Per Share Aggregate Intrinsic Value (in thousands, except price per share data) Balance, December 27, 2014 - outstanding 14,077 $ 2.01 7.2 — Granted 7,203 5.82 — $ 2.58 Exercised (797 ) 1.10 — — Forfeited and expired (633 ) 3.88 — — Balance, December 26, 2015 19,850 3.37 7.1 — Granted 4,039 6.35 — 2.71 Exercised (125 ) 3.49 — — Forfeited and expired (1,429 ) 4.54 — — Balance, December 31, 2016 22,335 3.66 6.6 — Granted 6,083 7.88 — 3.73 Exercised (963 ) 2.54 — — Forfeited and expired (1,119 ) 5.85 — — Balance, December 31, 2017 - outstanding 26,336 $ 4.59 6.4 — $ 1,242,901 Options exercisable at December 31, 2017 15,311 $ 3.00 4.6 — $ 746,939
Schedule of Share-based Compensation Expense Included in Consolidated Statements of Operations	The following table shows total stock-based compensation expense included in the accompanying Consolidated Statements of Operations for the years ended December 31, 2017, 2016 and December 26, 2015: Year Ended December 31, 2017 December 31, 2016 December 26, 2015 (in thousands) Cost of player revenue $ 145 $ 136 $ 90 Cost of platform revenue 81 224 54 Research and development 4,714 2,766 1,685 Sales and marketing 2,817 2,292 1,678 General and administrative 3,196 2,788 1,777 Total stock-based compensation $ 10,953 $ 8,206 $ 5,284
Summary of Assumptions Used to Value Stock-Based Awards Granted	The assumptions used to value stock-based awards granted during the years ended December 31, 2017, 2016 and December 26, 2015 are as follows: Year Ended December 31, 2017 December 31, 2016 December 26, 2015 Dividend rate — — $ — Expected term (in years) 5.3 - 6.5 5.3 - 6.5 6.1 Risk-free interest rate 1.87 - 2.25% 1.33 - 1.95% 1.39 - 1.90% Expected volatility 39 - 44% 44 - 46% 43 - 46% Fair value of common stock $2.56 - $18.46 $5.64 - $6.60 $5.64 - $7.02
Summary of Restricted Stock Unit Activity	Pursuant to the 2017 Plan, the Company issued restricted stock units to employees. Restricted stock unit activity for the year ended December 31, 2017 is as follows: Shares Weighted Average Grant Date Fair Value (in thousands, except price per share data) Balance, December 31, 2016 - outstanding — $ — Awarded 274 43.55 Released — — Forfeited (2 ) 43.55 Balance, December 31, 2017 - outstanding 272 $ 43.55
Convertible Preferred Stock Warrants
Summary of Assumptions Used to Value Stock-Based Awards Granted	Prior to the IPO, the Company valued convertible preferred stock warrants using the following assumptions in the Black-Scholes model: Year Ended December 31, 2016 December 26, 2015 Dividend rate $ — $ — Expected term (in years) 3.2 - 3.9 3.3 - 3.8 Risk-free interest rate 0.7% - 1.6% 1.1% - 1.4% Expected volatility 46.2% - 47.8% 42.0% - 46.9%
Schedule of Convertible Preferred Stock Warrants	Immediately prior to the IPO, outstanding convertible preferred stock warrants were as follows: Series Number Outstanding IPO closing date Number Outstanding December 31, 2016 Issuance Date Exercise Price Original Term (in thousands, except price per share data) C-2 1,250 1,250 July 13, 2011 $ 0.64931 10 years D 250 250 October 17, 2011 2.37840 10 years D 168 168 March 12, 2012 2.37840 10 years D 63 63 April 27, 2012 2.37840 10 years E 86 86 April 27, 2012 3.48546 10 years H 409 — June 9, 2017 9.17340 10 years Total 2,226 1,817

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments And Contingencies Disclosure [Abstract]
Schedule of Future Minimum Lease Payments under All Operating Leases	Future minimum lease payments under all operating leases as of December 31, 2017, are as follows: Year Ending December 31, Operating Leases (in thousands) 2018 $ 11,683 2019 11,764 2020 10,678 2021 1,112 2022 1,090 Thereafter 2,229 Less: Sublease rental income (5,153 ) Total $ 33,403
Summary of Company’s Exit Liability Activity	A summary of the Company’s exit liability activity for the year ended December 31, 2017 and 2016, is as follows: December 31, 2017 December 31, 2016 (in thousands) Beginning balance $ 2,085 $ - Change in estimated loss from exit 525 3,804 Non-cash adjustment - 1,120 Amortization of liability (1,831 ) (2,839 ) Ending balance $ 779 $ 2,085

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of Components of Loss Before Income Taxes	The components of loss before income taxes consist of the following: Year Ended December 31, 2017 December 31, 2016 December 26, 2015 (in thousands) United States $ (63,831 ) $ (42,977 ) $ (41,696 ) Foreign 637 430 1,232 Net loss before income taxes $ (63,194 ) $ (42,547 ) $ (40,464 )
Schedule of Income Tax Expense	The income tax expense consisted of the following: Year Ended December 31, 2017 December 31, 2016 December 26, 2015 (in thousands) Current: Federal $ — $ — $ — State 89 50 71 Foreign 674 160 76 763 210 147 Deferred: Federal — — — State — — — Foreign (448 ) 1 — Total $ 315 $ 211 $ 147
Schedule of Reconciliation of Statutory Federal Income Tax Rate to Effective Tax Rate	The following is a reconciliation of the statutory federal income tax rate to the Company’s effective tax rate: Year Ended December 31, 2017 December 31, 2016 December 26, 2015 U.S. federal income tax at statutory rate 34.0 % 34.0 % 34.0 % U.S. state and local income taxes (0.2 ) (0.1 ) (0.2 ) Change in valuation allowance 19.0 (36.9 ) (33.7 ) Federal research and development tax credit 5.2 4.8 3.9 Convertible preferred stock warrants (21.7 ) 0.7 (1.5 ) Stock-based compensation 1.2 (2.5 ) (1.7 ) Permanent items (1.1 ) (0.2 ) (1.1 ) Foreign rate differential 0.2 — 0.4 Tax rate change (36.4 ) — — Other (0.7 ) (0.2 ) (0.5 ) Effective tax rate (0.5 )% (0.4 )% (0.4 )%
Summary of Significant Components of Deferred Income Tax Assets and Liabilities	Significant components of the Company’s deferred income tax assets and liabilities consist of the following: December 31, 2017 December 31, 2016 (in thousands) Deferred tax assets: Net operating loss carryforwards $ 34,843 $ 46,954 Reserves and accruals 13,577 15,575 Research and development credits 15,475 10,555 Depreciation and amortization 288 1,568 Stock-based compensation 4,098 4,068 Total deferred tax assets 68,281 78,720 Valuation allowance (68,219 ) (78,695 ) Net deferred tax assets $ 62 $ 25
Summary of Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows: December 31, 2017 December 31, 2016 (in thousands) Unrecognized tax benefits at beginning of year $ 4,368 $ 2,917 Gross increase for tax positions of current years 1,475 1,246 Gross increase for tax positions of prior year — 205 Gross decrease for tax positions of prior years — — Unrecognized tax benefits balance at end of year $ 5,843 $ 4,368

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Summary of Calculation of Basic and Diluted Net Loss Per Share	The table presents the calculation of basic and diluted net loss per share as follows: Year Ended December 31, 2017 December 31, 2016 December 26, 2015 (in thousands, except per share data) Numerator: Net loss allocable to common stockholders $ (63,509 ) $ (42,758 ) $ (40,611 ) Denominator: Weighted-average shares used in computing net loss per share, basic and diluted 28,308 4,746 4,030 Net loss per share, basic and diluted $ (2.24 ) $ (9.01 ) $ (10.08 )
Schedule of Antidilutive Securities Excluded from Calculation of Diluted Net Loss Per Share	The potential common shares that were excluded from the calculation of diluted net loss per share because their effect would have been antidilutive for the periods presented are as follows: Year Ended December 31, 2017 December 31, 2016 December 26, 2015 (in thousands) Equity awards to purchase common stock 26,608 22,335 19,850 Unvested shares of common stock issued upon early exercise of stock options 57 3 12 Warrants to purchase common stock 184 375 542 Warrants to purchase convertible preferred stock - 1,817 1,817 Convertible preferred stock - 80,844 80,844 Total 26,849 105,374 103,065

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Schedule of Customer Accounting for 10% or More of Segment Revenue	Customers accounting for 10% or more of segment revenue, net, were as follows: Year Ended December 31, 2017 December 31, 2016 December 26, 2015 Player segment revenue Customer A 15 % 18 % 19 % Customer B 12 11 12 Customer C 34 32 26 Platform segment revenue Customer B * % 15 % 31 % Customer F * * 11 Customer E 13 % 10 * * Less than 10%

Quarterly Financial Data (Una32

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Summary of the Company's Information on Total Revenue, Gross Profit, Net Income (Loss) and Earnings Per Share by Quarter	The following table summarizes the Company’s information on total revenue, gross profit, net income (loss) and earnings per share by quarter for the years ended December 31, 2017 and 2016 Three Months Ended Dec 31, 2017 Sep 30, 2017 Jun 30, 2017 Mar 31, 2017 Dec 31, 2016 Oct 1, 2016 Jul 2, 2016 Apr 2, 2016 (in thousands, except per share amounts) Total Revenue $ 188,261 $ 124,782 $ 99,627 $ 100,093 $ 147,340 $ 89,053 $ 83,809 $ 78,447 Gross Profit 73,461 49,895 37,637 38,840 44,663 26,050 25,076 25,256 Net income (loss) 6,941 (46,235 ) (15,513 ) (8,702 ) 3,227 (12,743 ) (14,109 ) (19,133 ) Net income attributable to participating securities - - - - 3,227 - - - Net income (loss) attributable to common stockholders 6,941 (46,235 ) (15,513 ) (8,702 ) - (12,743 ) (14,109 ) (19,133 ) Basic net income (loss) per share attributable to common stockholders 0.07 (8.79 ) (3.18 ) (1.79 ) - (2.66 ) (2.98 ) (4.10 ) Diluted net income (loss) per share attributable to common stockholders 0.06 (8.79 ) (3.18 ) (1.79 ) - (2.66 ) (2.98 ) (4.10 )

The Company - Additional Inform

The Company - Additional Information (Details) $ / shares in Units, $ in Thousands, shares in Millions	Oct. 02, 2017USD ($)ClassesofStockVote$ / sharesshares	Dec. 31, 2017USD ($)segment	Dec. 26, 2015USD ($)
Business And Organization [Line Items]
Conversion date		Feb. 1, 2008
Number of reportable segments operates | segment		2
Offering costs incurred			$ 68
Number of classes of authorized common stock | ClassesofStock	2
Class A Common Stock
Business And Organization [Line Items]
Number of votes per share | Vote	1
Class B Common Stock
Business And Organization [Line Items]
Number of votes per share | Vote	10
Initial Public Offering | Class B Common Stock Warrants
Business And Organization [Line Items]
Warrants conversion ratio	100.00%
Initial Public Offering | Class A Common Stock
Business And Organization [Line Items]
Initial public offering completed date	Oct. 2, 2017
Number of shares sold | shares	10.4
Share sold price per share | $ / shares	$ 14
Net proceeds from shares sold	$ 134,800
Underwriting discounts and commissions	10,100
Offering costs incurred	$ 3,100	$ 3,100
Initial Public Offering | Class B Common Stock
Business And Organization [Line Items]
Convertible preferred stock, Shares converted | shares	80.8
Stock conversion ratio	100.00%
Over-Allotment Option | Class A Common Stock
Business And Organization [Line Items]
Number of shares sold | shares	1.4

Summary of Significant Accoun34

Summary of Significant Accounting Policies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2017USD ($)FinancialInstitution	Dec. 31, 2016USD ($)	Dec. 26, 2015USD ($)	Jan. 01, 2018USD ($)
Summary Of Significant Accounting Policies [Line Items]
Foreign currency gain (loss)	$ 100,000	$ (400,000)
Number of financial institutions which manage cash balances | FinancialInstitution	1
Impairment of goodwill	$ 0
Impairment of long-lived assets	0
Advertising costs	$ 3,400,000	$ 3,900,000	$ 4,100,000
Cash
Summary Of Significant Accounting Policies [Line Items]
Percentage of cash balances	95.00%	94.00%
Nonemployees
Summary Of Significant Accounting Policies [Line Items]
Stock option vesting period	4 years
Leasehold Improvements
Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives	5 years
Property and equipment, estimated useful lives description	shorter of the lease term or their estimated useful lives, which is generally five years
Website and Internal-Use Software
Summary Of Significant Accounting Policies [Line Items]
Capitalized costs	$ 2,600,000	$ 1,800,000	700,000
Amortized expenses	$ 1,100,000	700,000	$ 300,000
Estimated useful life	2 years
Minimum
Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives	18 months
Minimum | Subsequent Event
Summary Of Significant Accounting Policies [Line Items]
Decrease in accumulated deficit				$ (32,000,000)
Maximum
Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives	5 years
Maximum | Subsequent Event
Summary Of Significant Accounting Policies [Line Items]
Decrease in accumulated deficit				$ (42,000,000)
Internal-Use Software
Summary Of Significant Accounting Policies [Line Items]
Impairment of long-lived assets		$ 300,000

Summary of Significant Accoun35

Summary of Significant Accounting Policies - Schedules of Customer Concentration by Risk Factor (Details) - Customer Concentration Risk	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 26, 2015
Net Revenue | Customer A
Concentration Risk [Line Items]
Concentration risk		13.00%	16.00%
Net Revenue | Customer B
Concentration Risk [Line Items]
Concentration risk	10.00%	12.00%	15.00%
Net Revenue | Customer C
Concentration Risk [Line Items]
Concentration risk	20.00%	24.00%	23.00%
Net Revenue | Customer E
Concentration Risk [Line Items]
Concentration risk	10.00%
Accounts Receivable | Customer A
Concentration Risk [Line Items]
Concentration risk		12.00%
Accounts Receivable | Customer B
Concentration Risk [Line Items]
Concentration risk		11.00%
Accounts Receivable | Customer C
Concentration Risk [Line Items]
Concentration risk		17.00%
Accounts Receivable | Customer D
Concentration Risk [Line Items]
Concentration risk	16.00%	17.00%

Business Combination - Addition

Business Combination - Additional Information (Details) $ in Thousands, shares in Millions	Sep. 06, 2017USD ($)Foundershares	Dec. 31, 2017USD ($)
Business Acquisition [Line Items]
Aggregate purchase price, Paid		$ 2,959
Goodwill		1,382
Amortization of intangible assets expense		200
Estimated future amortization expenses for intangible asset for 2018		600
Estimated future amortization expenses for intangible asset for 2019		600
Estimated future amortization expenses for intangible asset for 2020		500
Estimated future amortization expenses for intangible asset for 2021		300
Denmark
Business Acquisition [Line Items]
Date of acquisition	Sep. 6, 2017
Aggregate purchase price	$ 3,500
Aggregate purchase price, Paid	$ 3,000
Aggregate purchase price, Payable		$ 500
Number of founders who received shares | Founder	2
Acquisition related cost which included in general and administrative expenses	$ 400
Repurchase period for shares issued under business acquisition	3 years
Goodwill	$ 1,400
Identifiable intangible assets acquired	$ 2,200
Identifiable intangible assets, expected useful life	4 years
Denmark | Class B Common Stock
Business Acquisition [Line Items]
Shares of common stock issued | shares	0.1

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Accounts Receivable, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 26, 2015
Valuation And Qualifying Accounts Disclosure [Line Items]
Gross accounts receivable	$ 138,292	$ 95,686
Allowance for accounts receivable	(17,739)	(16,213)
Total Accounts Receivable—net	120,553	79,473
Allowance for Sales Returns
Valuation And Qualifying Accounts Disclosure [Line Items]
Allowance for accounts receivable	(6,907)	(6,916)	$ (9,514)
Allowance for Sales Incentives
Valuation And Qualifying Accounts Disclosure [Line Items]
Allowance for accounts receivable	(10,442)	(8,503)	$ (7,642)
Other Allowances
Valuation And Qualifying Accounts Disclosure [Line Items]
Allowance for accounts receivable	$ (390)	$ (794)

Balance Sheet Components - Sc38

Balance Sheet Components - Schedule of Allowance for Sales Returns (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	$ (16,213)
Ending balance	(17,739)	$ (16,213)
Allowance for Sales Returns
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	(6,916)	(9,514)
Charged to revenue	(19,089)	(20,810)
Utilization of sales return/incentive reserve	19,098	23,408
Ending balance	$ (6,907)	$ (6,916)

Balance Sheet Components - Sc39

Balance Sheet Components - Schedule of Allowance for Sales Incentives (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	$ (16,213)
Ending balance	(17,739)	$ (16,213)
Allowance for Sales Incentives
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	(8,503)	(7,642)
Charged to revenue	(44,264)	(36,626)
Utilization of sales return/incentive reserve	42,325	35,765
Ending balance	$ (10,442)	$ (8,503)

Balance Sheet Components - Sc40

Balance Sheet Components - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property Plant And Equipment [Line Items]
Total property and equipment	$ 27,516	$ 17,342
Accumulated depreciation and amortization	(12,780)	(7,814)
Property and Equipment, net	14,736	9,528
Computer and Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	11,631	8,787
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment	8,437	4,201
Website and Internal-Use Software
Property Plant And Equipment [Line Items]
Total property and equipment	5,461	2,902
Office Equipment and Furniture
Property Plant And Equipment [Line Items]
Total property and equipment	$ 1,987	$ 1,452

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 26, 2015
Balance Sheet Related Disclosures [Abstract]
Depreciation and amortization	$ 5.2	$ 5.3	$ 2.6

Balance Sheet Components - Sc42

Balance Sheet Components - Schedule of Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accrued Liabilities Current [Abstract]
Accrued royalty expense	$ 17,165	$ 14,940
Accrued inventory	2,382	4,274
Accrued payroll and related expenses	8,699	5,342
Accrued cost of revenue	12,210	7,264
Accrued payments to content publishers	24,037	8,554
Sales tax and tax related liabilities	751	769
Other accrued expenses	7,100	5,013
Total Accrued Liabilities	$ 72,344	$ 46,156

Balance Sheet Components - Sc43

Balance Sheet Components - Schedule of Deferred Revenue (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred Revenue Arrangement [Line Items]
Deferred revenue, current portion	$ 34,501	$ 23,952
Deferred revenue, non-current portion	48,511	29,084
Total Deferred Revenue	83,012	53,036
Player
Deferred Revenue Arrangement [Line Items]
Deferred revenue, current portion	15,479	13,611
Deferred revenue, non-current portion	5,837	5,215
Platform
Deferred Revenue Arrangement [Line Items]
Deferred revenue, current portion	19,022	10,341
Deferred revenue, non-current portion	$ 42,674	$ 23,869

Fair Value Disclosure - Summary

Fair Value Disclosure - Summary of Reconciliation of the Preferred Stock Warrant Liability Measured and Recorded at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 26, 2015
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Reclassification to APIC upon conversion to common warrants		$ 52,355
Convertible Preferred Stock Warrant Liability
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Convertible preferred stock warrant liability — beginning balance		9,990	$ 10,878	$ 10,787
Fair value of new warrants issued		2,032
Change in fair value	[1]	40,333	(888)	1,768
Reclassification to preferred stock upon exercise				(1,677)
Reclassification to APIC upon conversion to common warrants		$ (52,355)
Convertible preferred stock warrant liability — ending balance			$ 9,990	$ 10,878
[1]	Recognized in the consolidated statements of operations within other expense—net.

Debt - Additional Information (

Debt - Additional Information (Details) - USD ($) $ / shares in Units, shares in Thousands	Oct. 31, 2017	Oct. 02, 2017	Jun. 30, 2017	May 31, 2015	Jul. 31, 2011	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Letters of credit outstanding						$ 1,500,000
Loss from extinguishment of debt						$ 2,338,000
Class B Common Stock
Debt Instrument [Line Items]
Warrants outstanding						200
Series H Convertible Preferred Stock Warrants
Debt Instrument [Line Items]
Warrants outstanding		409
Warrants, exercise price		$ 9.17340
Warrants, exercisable period		10 years
Bank - Term Loan
Debt Instrument [Line Items]
Duration of remaining amount available			24 months
Loss from extinguishment of debt						$ 2,300,000
Amendment to Loan and Security Agreement | Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity					$ 7,500,000
Length of the term loan borrowing					12 months
Amendment to Loan and Security Agreement | Bank - Term Loan
Debt Instrument [Line Items]
Maximum borrowing capacity					$ 5,000,000
Amount borrowed					$ 4,500,000
Line of credit facility final payment fees, percent					2.00%
Interest rate on line of credit					10.00%
Length of the term loan borrowing					48 months
Amendment to Loan and Security Agreement | Prime Rate | Bank - Term Loan
Debt Instrument [Line Items]
Basis spread on variable rate					1.75%
Restated 2014 LSA | Bank - Term Loan
Debt Instrument [Line Items]
Maximum borrowing capacity						$ 5,000,000
Line of credit, financial covenant description						The Restated 2014 LSA agreement contains a financial covenant to maintain a minimum required adjusted quick ratio (calculated as the sum of cash maintained with the Bank and the Bank’s affiliates and net billed account receivable balances, divided by current liabilities plus all outstanding obligations to the Bank under the revolving line, less deferred revenue), and non-financial covenants including providing the audited annual financial statements to the bank within 180 days following the year end.
Restated 2014 LSA | Bank - Term Loan | Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity						$ 30,000,000
First Amendment To 2014 Restated Loan and Security Agreement | Bank - Term Loan
Debt Instrument [Line Items]
Basis spread on variable rate				2.50%
Line of credit, financial covenant description						The advances under the first amendment to the Restated LSA carry a floating per annum interest rate equal to the prime rate or the prime rate plus 2.5% depending on certain ratios. The first amendment further changed the financial covenant to maintain a current ratio (calculated as current assets, divided by current liabilities less deferred revenue), greater than or equal to 1.1.
Current ratio				110.00%
Second Amendment To Restated 2014 Loan and Security Agreement | Bank - Term Loan
Debt Instrument [Line Items]
Amount borrowed						$ 0	$ 15,000,000
Interest rate on line of credit						4.31%	3.75%
Minimum current ratio required under financial covenant			1.25%
Letters of credit outstanding						$ 1,500,000	$ 900,000
Second Amendment To Restated 2014 Loan and Security Agreement | Prime Rate | Bank - Term Loan
Debt Instrument [Line Items]
Basis spread on variable rate			1.00%
Second Amendment To Restated 2014 Loan and Security Agreement | LIBOR | Bank - Term Loan
Debt Instrument [Line Items]
Basis spread on variable rate			2.75%
2017 Subordinated Loan Agreement | Bank - Term Loan
Debt Instrument [Line Items]
Maximum borrowing capacity			$ 40,000,000
Subordinated loan agreement minimum borrowing capacity			$ 25,000,000
Facility fee, percentage			1.00%
LIBOR Floor rate			1.00%
Payment in kind interest fees, percent			2.50%
2017 Subordinated Loan Agreement | Bank - Term Loan | Class B Common Stock
Debt Instrument [Line Items]
Cancellation of warrants to purchase common stock	100
2017 Subordinated Loan Agreement | Bank - Term Loan | Series H Convertible Preferred Stock Warrants
Debt Instrument [Line Items]
Warrants outstanding			400
Warrants, exercise price			$ 9.17340
Warrants, exercisable period			10 years
2017 Subordinated Loan Agreement | Bank - Term Loan | Minimum
Debt Instrument [Line Items]
Line of credit facility final payment fees, percent			1.00%
Remaining amount to be drawn as installment			$ 5,000,000
2017 Subordinated Loan Agreement | Bank - Term Loan | Maximum
Debt Instrument [Line Items]
Line of credit facility final payment fees, percent			4.00%
2017 Subordinated Loan Agreement | Prime Rate | Bank - Term Loan
Debt Instrument [Line Items]
Basis spread on variable rate			3.50%
2017 Subordinated Loan Agreement | LIBOR | Bank - Term Loan
Debt Instrument [Line Items]
Basis spread on variable rate			6.50%

Stockholders' Equity (Deficit46

Stockholders' Equity (Deficit) - Schedule of Convertible Preferred Stock (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Nov. 30, 2015
Class Of Stock [Line Items]
Price	$ 0.0001	$ 0.0001
Shares Authorized	0	84,368
Shares Outstanding	0	80,844
Liquidation Preference		$ 213,109
Series A Convertible Preferred Stock
Class Of Stock [Line Items]
Price		$ 0.36312
Shares Authorized		23,020
Shares Outstanding		23,020
Liquidation Preference		$ 8,359
Series B Convertible Preferred Stock
Class Of Stock [Line Items]
Price		$ 0.93808
Shares Authorized		6,396
Shares Outstanding		6,396
Liquidation Preference		$ 6,000
Series C-1 Convertible Preferred Stock
Class Of Stock [Line Items]
Price		$ 0.54109
Shares Authorized		9,240
Shares Outstanding		9,240
Liquidation Preference		$ 5,000
Series C-2 Convertible Preferred Stock
Class Of Stock [Line Items]
Price		$ 0.64931
Shares Authorized		8,950
Shares Outstanding		7,700
Liquidation Preference		$ 5,000
Series D Convertible Preferred Stock
Class Of Stock [Line Items]
Price		$ 2.37840
Shares Authorized		4,686
Shares Outstanding		4,205
Liquidation Preference		$ 10,000
Series E Convertible Preferred Stock
Class Of Stock [Line Items]
Price		$ 4.35679
Shares Authorized		11,161
Shares Outstanding		11,075
Liquidation Preference		$ 48,250
Series F Convertible Preferred Stock
Class Of Stock [Line Items]
Price		$ 5.43396
Shares Authorized		11,042
Shares Outstanding		11,042
Liquidation Preference		$ 60,000
Series G Convertible Preferred Stock
Class Of Stock [Line Items]
Price		$ 7.79730
Shares Authorized		3,206
Shares Outstanding		3,206
Liquidation Preference		$ 25,000
Series H Convertible Preferred Stock
Class Of Stock [Line Items]
Price		$ 9.17340	$ 9.17340
Shares Authorized		6,667
Shares Outstanding		4,960
Liquidation Preference		$ 45,500

Stockholders' Equity (Deficit47

Stockholders' Equity (Deficit) - Convertible Preferred Stock - Additional Information (Details) - shares shares in Thousands	Oct. 02, 2017	Dec. 31, 2017	Dec. 31, 2016
Class Of Stock [Line Items]
Preferred stock, shares authorized	10,000	10,000	0
Preferred stock, shares issued		0	0
Preferred stock, shares outstanding		0	0
Initial Public Offering | Class B Common Stock
Class Of Stock [Line Items]
Convertible preferred stock, Shares converted	80,800
Stock conversion ratio	100.00%

Stockholders' Equity (Deficit48

Stockholders' Equity (Deficit) - Common Stock - Additional Information (Details)	12 Months Ended
	Dec. 31, 2017Class
Class Of Stock [Line Items]
Number of classes	2
Class A Common Stock
Class Of Stock [Line Items]
Common stock, voting right	one vote for each share
Class B Common Stock
Class Of Stock [Line Items]
Common stock, voting right	ten votes for each share

Stockholders' Equity (Deficit49

Stockholders' Equity (Deficit) - Schedule of Reserved Shares of Common Stock for Issuance (Details) shares in Thousands	Dec. 31, 2017shares
Class Of Stock [Line Items]
Common stock reserved for issuance	38,994
Outstanding Warrants [Member]
Class Of Stock [Line Items]
Common stock reserved for issuance	184
Equity Incentive Plan
Class Of Stock [Line Items]
Common stock awards issued under equity incentive plan	26,608
Common stock awards available for grant under equity incentive plan	12,202

Stockholders' Equity (Deficit50

Stockholders' Equity (Deficit) - Equity Incentive Plans - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 26, 2015
Class Of Stock [Line Items]
Stock options expiration term	10 years
2008 Plan
Class Of Stock [Line Items]
Percentage Of Voting Rights	10.00%
Stock option vesting period	4 years
Stock options expiration term	10 years
2008 Plan | Minimum | 10% Shareholder
Class Of Stock [Line Items]
Stock option fair market value at the date of grant, percent	110.00%
2017 Plan
Class Of Stock [Line Items]
Stock option vesting period	4 years
Stock options expiration term	10 years
Equity Incentive Plan
Class Of Stock [Line Items]
Intrinsic value of share based options exercised	$ 20.4	$ 0.4	$ 3.9

Stockholders' Equity (Deficit51

Stockholders' Equity (Deficit) - Schedule of Activity Under Equity Incentive Plan (Details) - 2008 Plan and 2017 Plan - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance, Number of shares	22,335	19,850	14,077
Granted, Number of shares	6,083	4,039	7,203
Exercised, Number of shares	(963)	(125)	(797)
Forfeited and expired, Number of shares	(1,119)	(1,429)	(633)
Balance, Number of shares	26,336	22,335	19,850	14,077
Options exercisable at December 31, 2017, Number of shares	15,311
Balance, Weighted average exercise price	$ 3.66	$ 3.37	$ 2.01
Granted, Weighted average exercise price	7.88	6.35	5.82
Exercised, Weighted average exercise price	2.54	3.49	1.10
Forfeited and expired, Weighted average exercise price	5.85	4.54	3.88
Balance, Weighted average exercise price	4.59	$ 3.66	$ 3.37	$ 2.01
Options exercisable at December 31, 2017, Weighted average exercise price	$ 3
Balance, Weighted average remaining contractual life	6 years 4 months 24 days	6 years 7 months 6 days	7 years 1 month 6 days	7 years 2 months 12 days
Options exercisable at December 31, 2017, Weighted average remaining contractual life	4 years 7 months 6 days
Granted, Weighted average grant date fair value per share	$ 3.73	$ 2.71	$ 2.58
Outstanding, ending balance	$ 1,242,901
Options exercisable, ending balance	$ 746,939

Stockholders' Equity (Deficit52

Stockholders' Equity (Deficit) - Stock-based Compensation - Additional Information (Details)	12 Months Ended
	Dec. 31, 2017
Class Of Stock [Line Items]
Stock options expiration term	10 years
Employee Stock Option | Tranche One
Class Of Stock [Line Items]
Stock granted to employees vesting rights, percentage	25.00%
Employee Stock Option | Tranche Two
Class Of Stock [Line Items]
Stock granted to employees vesting rights, terms of award	one year and then 1/48th monthly thereafter
Restricted Stock Units | Tranche One
Class Of Stock [Line Items]
Stock granted to employees vesting rights, percentage	25.00%
Restricted Stock Units | Tranche Two
Class Of Stock [Line Items]
Stock granted to employees vesting rights, terms of award	one year and then 1/16th quarterly thereafter

Stockholders' Equity (Deficit53

Stockholders' Equity (Deficit) - Schedule of Share-based Compensation Expense Included in Consolidated Statements of Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 26, 2015
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 10,953	$ 8,206	$ 5,284
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	4,714	2,766	1,685
Sales and Marketing
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	2,817	2,292	1,678
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	3,196	2,788	1,777
Player | Cost of Revenue
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	145	136	90
Platform | Cost of Revenue
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 81	$ 224	$ 54

Stockholders' Equity (Deficit54

Stockholders' Equity (Deficit) - Expected Dividends - Additional Information (Details)	12 Months Ended
	Dec. 31, 2017USD ($)
Equity [Abstract]
Expected dividend	$ 0

Stockholders' Equity (Deficit55

Stockholders' Equity (Deficit) - Summary of Assumptions Used to Value Stock-Based Awards Granted (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 26, 2015
Minimum
Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions And Methodology [Abstract]
Expected term (in years)	5 years 3 months 19 days	5 years 3 months 19 days	6 years 1 month 6 days
Risk-free interest rate	1.87%	1.33%	1.39%
Expected volatility	39.00%	44.00%	43.00%
Fair value of common stock	$ 2.56	$ 5.64	$ 5.64
Maximum
Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions And Methodology [Abstract]
Expected term (in years)	6 years 6 months	6 years 6 months
Risk-free interest rate	2.25%	1.95%	1.90%
Expected volatility	44.00%	46.00%	46.00%
Fair value of common stock	$ 18.46	$ 6.60	$ 7.02

Stockholders' Equity (Deficit56

Stockholders' Equity (Deficit) - Risk-Free Interest Rate - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Unrecognized stock compensation expense	$ 32.3
Expected weighted average period to recognize unrecognized stock compensation expense	2 years 8 months 12 days

Stockholders' Equity (Deficit57

Stockholders' Equity (Deficit) - Stock Option Repricing - Additional Information (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	1 Months Ended	12 Months Ended
	Nov. 30, 2016	Dec. 31, 2017	Oct. 31, 2016
Minimum
Class Of Stock [Line Items]
Stock option exercise price per share			$ 5.64
Stock Option Repricing
Class Of Stock [Line Items]
Stock option exercise price per share	$ 5.64
Option conversion basis		one-for-one basis
Granted, Number of shares	5.1
Common stock price per share	$ 5.70
Common stock price per share	$ 7.02
Incremental stock-based compensation	$ 1
Expense related to vested shares	0.1
Expense related to unvested shares	$ 0.9

Stockholders' Equity (Deficit58

Stockholders' Equity (Deficit) - Summary of Restricted Stock Unit Activity (Details) - Restricted Stock Units shares in Thousands	12 Months Ended
	Dec. 31, 2017$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Shares, Awarded | shares	274
Shares, Forfeited | shares	(2)
Ending balance, Shares outstanding | shares	272
Weighted Average Grant Date Fair Value, Awarded | $ / shares	$ 43.55
Weighted Average Grant Date Fair Value, Forfeited | $ / shares	43.55
Weighted Average Grant Date Fair Value, Ending balance | $ / shares	$ 43.55

Stockholders' Equity (Deficit59

Stockholders' Equity (Deficit) - Restricted Stock Units - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Unrecognized stock compensation expense	$ 32.3
Expected weighted average period to recognize unrecognized stock compensation expense	2 years 8 months 12 days
Restricted Stock Units
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Grant-date fair value of restricted stock units granted	$ 11.9
Unrecognized stock compensation expense	$ 11.6
Expected weighted average period to recognize unrecognized stock compensation expense	3 years 10 months 24 days

Stockholders' Equity (Deficit60

Stockholders' Equity (Deficit) - Common Stock Warrants - Additional Information (Details) - Common Stock Warrants - Class B Common Stock shares in Millions	1 Months Ended
	Jul. 31, 2017shares
Class Of Warrant Or Right [Line Items]
Conversion of common stock warrants	0.4
Number of common stock warrants exercise	0.4

Stockholders' Equity (Deficit61

Stockholders' Equity (Deficit) - Schedule of Convertible Preferred Stock Warrants (Details) - $ / shares shares in Thousands	Oct. 02, 2017	Dec. 31, 2016
Series C-2 Preferred Stock Warrants
Class Of Warrant Or Right [Line Items]
Number Outstanding IPO closing date	1,250	1,250
Issuance Date	Jul. 13, 2011
Warrants, exercise price	$ 0.64931
Warrants, exercisable period	10 years
Series D Preferred Stock Warrants | October 17, 2011
Class Of Warrant Or Right [Line Items]
Number Outstanding IPO closing date	250	250
Issuance Date	Oct. 17, 2011
Warrants, exercise price	$ 2.37840
Warrants, exercisable period	10 years
Series D Preferred Stock Warrants | March 12, 2012
Class Of Warrant Or Right [Line Items]
Number Outstanding IPO closing date	168	168
Issuance Date	Mar. 12, 2012
Warrants, exercise price	$ 2.37840
Warrants, exercisable period	10 years
Series D Preferred Stock Warrants | April 27, 2012
Class Of Warrant Or Right [Line Items]
Number Outstanding IPO closing date	63	63
Issuance Date	Apr. 27, 2012
Warrants, exercise price	$ 2.37840
Warrants, exercisable period	10 years
Series E Preferred Stock Warrants
Class Of Warrant Or Right [Line Items]
Number Outstanding IPO closing date	86	86
Issuance Date	Apr. 27, 2012
Warrants, exercise price	$ 3.48546
Warrants, exercisable period	10 years
Series H Convertible Preferred Stock Warrants
Class Of Warrant Or Right [Line Items]
Number Outstanding IPO closing date	409
Issuance Date	Jun. 9, 2017
Warrants, exercise price	$ 9.17340
Warrants, exercisable period	10 years
Convertible Preferred Stock Warrants
Class Of Warrant Or Right [Line Items]
Number Outstanding IPO closing date	2,226	1,817

Stockholders' Equity (Deficit62

Stockholders' Equity (Deficit) - Convertible Preferred Stock Warrants - Additional Information (Details) - Class B Common Stock shares in Millions	Dec. 31, 2017shares
Class Of Warrant Or Right [Line Items]
Warrants exercised	1.9
Warrants cancelled	0.1
Warrants issued	1.8
Warrants outstanding	0.2

Stockholder's Equity (Deficit)

Stockholder's Equity (Deficit) - Summary of Assumptions Used to Value Convertible Preferred Stock Warrants (Details) - Convertible Preferred Stock Warrants	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015
Minimum
Class Of Warrant Or Right [Line Items]
Expected term (in years)	3 years 2 months 12 days	3 years 3 months 19 days
Risk-free interest rate	0.70%	1.10%
Expected volatility	46.20%	42.00%
Maximum
Class Of Warrant Or Right [Line Items]
Expected term (in years)	3 years 10 months 25 days	3 years 9 months 18 days
Risk-free interest rate	1.60%	1.40%
Expected volatility	47.80%	46.90%

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)OfficeVendor	Dec. 31, 2016USD ($)	Dec. 26, 2015USD ($)
Commitments And Contingencies [Line Items]
Operating lease earliest expiration date	May 31, 2017
Operating lease latest expiration date	Feb. 28, 2021
Rent expense	$ 6,900	$ 4,600	$ 4,200
Future minimum lease payments, Number of office locations | Office	2
Future operating lease obligations	$ 33,403
Asset retirement obligations	$ 500	300
Purchase obligation not yet recognized description	At December 31, 2017, the Company had $1.1 million of obligations that are not reflected on the financial statements as they do not yet meet the criteria for asset and liability recognition.
Lease liability	$ 779	2,085
Letters of credit outstanding	$ 1,500
Letters of credit expiration date	Dec. 31, 2018
Accrued Liabilities
Commitments And Contingencies [Line Items]
Lease liability	$ 700
Other Noncurrent Liabilities
Commitments And Contingencies [Line Items]
Lease liability	$ 100
Manufacturing
Commitments And Contingencies [Line Items]
Number of vendors having purchase commitments | Vendor	1
Purchase commitments for inventory	$ 75,200	64,300
Loss on purchase obligation for inventory	600	$ 2,000
Content License
Commitments And Contingencies [Line Items]
Purchase obligation that do not yet Meet criteria for asset and liability recognition	$ 1,100
Player | Minimum
Commitments And Contingencies [Line Items]
Product Warranty Term	12 months
Player | Maximum
Commitments And Contingencies [Line Items]
Product Warranty Term	24 months
Los Gatos Lease Facility
Commitments And Contingencies [Line Items]
Future minimum lease payments expiration year	2,020
Future operating lease obligations	$ 19,200
Saratoga Lease Facility
Commitments And Contingencies [Line Items]
Future minimum lease payments expiration year	2,020
Future operating lease obligations	$ 7,500

Commitments and Contingencies65

Commitments and Contingencies - Schedule of Future Minimum Lease Payments under All Operating Leases (Details) $ in Thousands	Dec. 31, 2017USD ($)
Operating Leases Future Minimum Payments Due [Abstract]
2,018	$ 11,683
2,019	11,764
2,020	10,678
2,021	1,112
2,022	1,090
Thereafter	2,229
Less: Sublease rental income	(5,153)
Total	$ 33,403

Commitments and Contingencies66

Commitments and Contingencies - Summary of Company's Exit Liability Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Beginning balance	$ 2,085
Change in estimated loss from exit	525	$ 3,804
Non-cash adjustment		1,120
Amortization of liability	(1,831)	(2,839)
Ending balance	$ 779	$ 2,085

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Components of Loss Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 26, 2015
Income Tax Disclosure [Abstract]
United States	$ (63,831)	$ (42,977)	$ (41,696)
Foreign	637	430	1,232
Net loss before income taxes	$ (63,194)	$ (42,547)	$ (40,464)

Income Taxes - Schedule of Inco

Income Taxes - Schedule of Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 26, 2015
Current:
State	$ 89	$ 50	$ 71
Foreign	674	160	76
Current income tax expense	763	210	147
Deferred:
Foreign	(448)	1
Total	$ 315	$ 211	$ 147

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliation of Statutory Federal Income Tax Rate to Effective Tax Rate (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 26, 2015
Income Tax Disclosure [Abstract]
U.S. federal income tax at statutory rate	34.00%	34.00%	34.00%
U.S. state and local income taxes	(0.20%)	(0.10%)	(0.20%)
Change in valuation allowance	19.00%	(36.90%)	(33.70%)
Federal research and development tax credit	5.20%	4.80%	3.90%
Convertible preferred stock warrants	(21.70%)	0.70%	(1.50%)
Stock-based compensation	1.20%	(2.50%)	(1.70%)
Permanent items	(1.10%)	(0.20%)	(1.10%)
Foreign rate differential	0.20%		0.40%
Tax rate change	(36.40%)
Other	(0.70%)	(0.20%)	(0.50%)
Effective tax rate	(0.50%)	(0.40%)	(0.40%)

Income Taxes - Summary of Signi

Income Taxes - Summary of Significant Components of Deferred Income Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Net operating loss carryforwards	$ 34,843	$ 46,954
Reserves and accruals	13,577	15,575
Research and development credits	15,475	10,555
Depreciation and amortization	288	1,568
Stock-based compensation	4,098	4,068
Total deferred tax assets	68,281	78,720
Valuation allowance	(68,219)	(78,695)
Net deferred tax assets	$ 62	$ 25

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 26, 2015
Income Taxes Disclosure [Line Items]
Research and development tax credit carryforwards		$ 15,475,000	$ 10,555,000
Unrecognized tax benefits		5,843,000	$ 4,368,000	$ 2,917,000
Accrued interest and penalties		0
Unrecognized tax benefits that would impact effective tax rate		$ 0
US federal corporate tax rate		34.00%	34.00%	34.00%
Estimated re-measurement of deferred tax balance		$ 23,000,000
Research and Development Credits
Income Taxes Disclosure [Line Items]
Unrecognized tax benefits		5,800,000
Accounting Standards Update 2016-09
Income Taxes Disclosure [Line Items]
Previously unrecognized U.S. excess tax benefit recorded as deferred tax assets		1,300,000
Federal
Income Taxes Disclosure [Line Items]
Net operating loss carryforwards		$ 135,200,000
Net operating loss carryforwards, expiration beginning year		2,028
Research and development tax credit carryforwards		$ 13,400,000
Tax credit carryforwards, expiration beginning year		2,028
US federal corporate tax rate		35.00%
Federal | Scenario Forecast
Income Taxes Disclosure [Line Items]
US federal corporate tax rate	21.00%
State
Income Taxes Disclosure [Line Items]
Net operating loss carryforwards		$ 104,100,000
Net operating loss carryforwards, expiration beginning year		2,028
Research and development tax credit carryforwards		$ 9,100,000

Income Taxes - Summary of Recon

Income Taxes - Summary of Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Unrecognized tax benefits at beginning of year	$ 4,368	$ 2,917
Gross increase for tax positions of current years	1,475	1,246
Gross increase for tax positions of prior year		205
Unrecognized tax benefits balance at end of year	$ 5,843	$ 4,368

Related Party Disclosures - Add

Related Party Disclosures - Additional Information (Details) - Strategic Investors - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 26, 2015
Related Party Transaction [Line Items]
Revenue from related parties	$ 600,000	$ 700,000	$ 500,000
Receivable from related parties	500,000	100,000
Related party transaction expense	$ 400,000	$ 0

Retirement Plans - Additional I

Retirement Plans - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 26, 2015
Compensation And Retirement Disclosure [Abstract]
Employer contribution amount to plan	$ 0.3	$ 0.2	$ 0.2

Net Loss Per Share - Summary of

Net Loss Per Share - Summary of Calculation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Apr. 02, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 26, 2015
Numerator:
Net loss allocable to common stockholders	$ 6,941	$ (46,235)	$ (15,513)	$ (8,702)	$ 3,227	$ (12,743)	$ (14,109)	$ (19,133)	$ (63,509)	$ (42,758)	$ (40,611)
Denominator:
Weighted-average shares used in computing net loss per share, basic and diluted									28,308	4,746	4,030
Net loss per share, basic and diluted									$ (2.24)	$ (9.01)	$ (10.08)

Net Loss Per Share - Schedule o

Net Loss Per Share - Schedule of Antidilutive Securities Excluded from Calculation of Diluted Net Loss Per Share (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 26, 2015
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted net loss per share	26,849	105,374	103,065
Equity Awards to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted net loss per share	26,608	22,335	19,850
Unvested Shares of Common Stock Issued Upon Early Exercise of Stock Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted net loss per share	57	3	12
Warrants to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted net loss per share	184	375	542
Warrants To Purchase Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted net loss per share		1,817	1,817
Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted net loss per share		80,844	80,844

Segment Information - Additiona

Segment Information - Additional Information (Details) - segment	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Number of reportable segments operates	2
Net Revenue | Geographic Concentration Risk [Member] | International Market [Member] | Maximum
Segment Reporting Information [Line Items]
Concentration risk	10.00%	10.00%

Segment Information - Schedule

Segment Information - Schedule of Customer Accounting for 10% or More of Segment Revenue (Details) - Net Revenue - Customer Concentration Risk	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 26, 2015
Customer A
Entity Wide Revenue Major Customer [Line Items]
Concentration risk		13.00%	16.00%
Customer B
Entity Wide Revenue Major Customer [Line Items]
Concentration risk	10.00%	12.00%	15.00%
Customer C
Entity Wide Revenue Major Customer [Line Items]
Concentration risk	20.00%	24.00%	23.00%
Customer E
Entity Wide Revenue Major Customer [Line Items]
Concentration risk	10.00%
Player | Customer A
Entity Wide Revenue Major Customer [Line Items]
Concentration risk	15.00%	18.00%	19.00%
Player | Customer B
Entity Wide Revenue Major Customer [Line Items]
Concentration risk	12.00%	11.00%	12.00%
Player | Customer C
Entity Wide Revenue Major Customer [Line Items]
Concentration risk	34.00%	32.00%	26.00%
Platform | Customer B
Entity Wide Revenue Major Customer [Line Items]
Concentration risk		15.00%	31.00%
Platform | Customer F
Entity Wide Revenue Major Customer [Line Items]
Concentration risk			11.00%
Platform | Customer E
Entity Wide Revenue Major Customer [Line Items]
Concentration risk	13.00%	10.00%

Quarterly Financial Data (Una79

Quarterly Financial Data (Unaudited) - Summary of the Company's Information on Total Revenue, Gross Profit, Net Income (Loss) and Earnings Per Share by Quarter (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Apr. 02, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 26, 2015
Quarterly Financial Information Disclosure [Abstract]
Total net revenue	$ 188,261	$ 124,782	$ 99,627	$ 100,093	$ 147,340	$ 89,053	$ 83,809	$ 78,447	$ 512,763	$ 398,649	$ 319,857
Gross Profit	73,461	49,895	37,637	38,840	44,663	26,050	25,076	25,256	199,833	121,045	89,778
Net loss	6,941	(46,235)	(15,513)	(8,702)	3,227	(12,743)	(14,109)	(19,133)	$ (63,509)	$ (42,758)	$ (40,611)
Net income attributable to participating securities					$ 3,227
Net income (loss) attributable to common stockholders	$ 6,941	$ (46,235)	$ (15,513)	$ (8,702)		$ (12,743)	$ (14,109)	$ (19,133)
Basic net income (loss) per share attributable to common stockholders	$ 0.07	$ (8.79)	$ (3.18)	$ (1.79)		$ (2.66)	$ (2.98)	$ (4.10)
Diluted net income (loss) per share attributable to common stockholders	$ 0.06	$ (8.79)	$ (3.18)	$ (1.79)		$ (2.66)	$ (2.98)	$ (4.10)