Roku (ROKU) 10-Q 9 Nov 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Nov. 03, 2017
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Trading Symbol	ROKU
Entity Registrant Name	Roku, Inc.
Entity Central Index Key	1,428,439
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Class A Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		18,106,218
Class B Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		79,718,676

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Current Assets:
Cash	$ 66,918	$ 34,562
Accounts receivable, net of allowances	84,840	79,325
Receivable from related parties	153	148
Inventories	35,450	43,568
Prepaid expenses and other current assets	7,702	4,981
Deferred cost of revenue	2,448	2,636
Total current assets	197,511	165,220
Property and equipment, net	12,807	9,528
Deferred cost of revenue, noncurrent portion	4,975	3,815
Intangible assets	2,215
Goodwill	1,554
Other noncurrent assets	6,440	515
Total Assets	225,502	179,078
Current Liabilities:
Accounts payable	49,171	31,397
Accrued liabilities	65,498	46,156
Current portion of long-term debt		15,000
Deferred revenue, current portion	30,822	23,952
Total current liabilities	145,491	116,505
Long-term debt, less current portion	23,043
Preferred stock warrant liability	52,355	9,990
Noncurrent deferred revenue	38,802	29,084
Other long-term liabilities	8,604	4,143
Total Liabilities	268,295	159,722
Commitments and Contingencies (Note 7)
Convertible Preferred Stock:
Convertible preferred stock	213,180	213,180
Stockholders’ Deficit:
Common stock	1
Additional paid-in capital	34,305	26,005
Accumulated deficit	(290,279)	(219,829)
Total stockholders’ deficit	(255,973)	(193,824)
Total Liabilities, Convertible Preferred Stock and Stockholders’ Deficit	$ 225,502	$ 179,078

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Net Revenue:
Total net revenue	$ 124,782	$ 89,053	$ 324,502	$ 251,309
Cost of Revenue:
Total cost of revenue	74,887	63,003	198,130	174,927
Gross Profit:
Total gross profit	49,895	26,050	126,372	76,382
Operating Expenses:
Research and development	28,532	18,229	76,650	56,700
Sales and marketing	16,216	12,844	44,938	39,089
General and administrative	13,039	9,078	33,894	27,333
Total operating expenses	57,787	40,151	155,482	123,122
Loss from Operations	(7,892)	(14,101)	(29,110)	(46,740)
Other Income (Expense), Net:
Interest expense	(815)	(32)	(1,286)	(163)
Change in fair value of preferred stock warrant liability	(37,682)	1,481	(40,333)	1,087
Other income (expense), net	212	(41)	423	(66)
Total other income (expense), net	(38,285)	1,408	(41,196)	858
Loss before income taxes	(46,177)	(12,693)	(70,306)	(45,882)
Income tax expense	58	50	144	103
Net loss attributable to common stockholders	$ (46,235)	$ (12,743)	$ (70,450)	$ (45,985)
Net loss per share attributable to common stockholders—basic and diluted	$ (8.79)	$ (2.66)	$ (14.09)	$ (9.73)
Weighted-average shares used in computing net loss per share attributable to common stockholders—basic and diluted	5,259,796	4,784,170	4,998,727	4,724,767
Player
Net Revenue:
Total net revenue, Goods	$ 67,254	$ 64,789	$ 184,583	$ 183,905
Cost of Revenue:
Total cost of revenue, Goods	61,925	56,156	165,047	155,531
Gross Profit:
Total gross profit	5,329	8,633	19,536	28,374
Platform
Net Revenue:
Total net revenue, Services	57,528	24,264	139,919	67,404
Cost of Revenue:
Total cost of revenue, Services	12,962	6,847	33,083	19,396
Gross Profit:
Total gross profit	$ 44,566	$ 17,417	$ 106,836	$ 48,008

Condensed Consolidated Stateme4

Condensed Consolidated Statements of Convertible Preferred Stock and Stockholders' Deficit (Unaudited) - 9 months ended Sep. 30, 2017 - USD ($) $ in Thousands	Total	Convertible Preferred Stock	Common Stock	Additional Paid-in Capital	Treasury Stock	Accumulated Deficit
Balance at Dec. 31, 2016	$ (193,824)			$ 26,005		$ (219,829)
Balance, Shares at Dec. 31, 2016	80,844,138	80,844,138
Balance at Dec. 31, 2016	$ 213,180	$ 213,180
Balance, Shares at Dec. 31, 2016			4,818,812
Issuance of common stock upon exercise of stock options	1,443		$ 1	1,442
Issuance of common stock upon exercise of stock options			445,995
Share repurchases	(671)				$ (671)
Share repurchases, shares			(92,637)
Vesting of early exercised stock options	12			12
Issuance of common stock pursuant to acquisition			108,332
Issuance of common stock shares upon expiration of warrants			357,283
Stock-based compensation expense	7,517			7,517
Net loss	(70,450)					(70,450)
Balance at Sep. 30, 2017	$ (255,973)		$ 1	$ 34,976	$ (671)	$ (290,279)
Balance, shares at Sep. 30, 2017	80,844,138	80,844,138
Balance at Sep. 30, 2017	$ 213,180	$ 213,180
Balance, Shares at Sep. 30, 2017			5,637,785

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Oct. 01, 2016
Cash flows from operating activities:
Net loss	$ (70,450)	$ (45,985)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	3,883	4,201
Impairment of assets		320
Stock-based compensation expense	7,517	6,016
Provision for doubtful accounts	17	278
Change in fair value of preferred stock warrant liability	40,333	(1,087)
Noncash interest expense	668	89
Loss on disposals of property and equipment	54	29
Loss from exit of facilities	232	3,804
Write-off of deferred initial public offering costs		594
Changes in operating assets and liabilities:
Due from related parties	(5)	165
Accounts receivable	(5,532)	(4,058)
Inventories	8,118	(19,738)
Prepaid expenses and other current assets	(2,867)	385
Deferred cost of revenue	(972)	(1,759)
Other noncurrent assets	(5,870)	445
Accounts payable	17,406	13,137
Accrued liabilities	17,662	20,193
Other long-term liabilities	4,410	959
Deferred revenue	16,588	9,102
Net cash provided by (used in) operating activities	31,192	(12,910)
Cash flows from investing activities:
Purchase of property and equipment	(6,671)	(7,380)
Purchase of business, net of cash acquired	(2,959)
Restricted cash	31	29
Net cash used in investing activities	(9,599)	(7,351)
Cash flows from financing activities:
Payments of costs related to initial public offering		(594)
Proceeds from borrowings, net	24,691
Repayments of borrowings	(15,000)	(15,000)
Proceeds from exercise of stock options, net of repurchases	1,072	366
Net cash provided by (used in) financing activities	10,763	(15,228)
Net Increase (Decrease) In Cash	32,356	(35,489)
Cash—Beginning of period	34,562	75,748
Cash—End of period	66,918	40,259
Supplemental disclosures of cash flow information:
Cash paid for interest	583	149
Cash paid for income taxes	162	132
Supplemental disclosures of noncash investing and financing activities:
Purchases of property and equipment recorded in accounts payable and accrued liabilities	836	$ 671
Issuance of convertible preferred stock warrants in connection with debt	2,032
Unpaid initial public offering costs	$ 2,992

The Company

The Company	9 Months Ended
	Sep. 30, 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 10,350,000 shares, including 1,350,000 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 $134,757,000, after deducting underwriting discounts and commissions of $10,143,000. Additionally, offering costs incurred by the Company are expected to total approximately $4,000,000. Upon the closing of the Company’s IPO, all outstanding shares of its convertible preferred stock automatically converted into 80,844,138 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.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation and Use of Estimates The condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (the “SEC”) regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements contained in our final prospectus filed pursuant to Rule 424(b) under the Securities Act of 1933, as amended, with the SEC on September 28, 2017 (the “Prospectus”). There have been no material changes in the Company’s significant accounting policies from those that were disclosed in the Prospectus, except as noted below. 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 the 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, the fair value of assets and liabilities acquired in business combinations and the fair value of the Company’s preferred stock and common stock. 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. To the extent that there are material differences between these estimates and actual results, the Company’s financial condition or operating results will be affected. Principles of Consolidation The condensed consolidated financial statements have been prepared in accordance with U.S. GAAP and includes the accounts of the Company and its wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated in consolidation. 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 condensed consolidated financial statements. Concentrations Customers accounting for 10% or more of the Company’s net revenue were as follows: Three Months Ended Nine Months Ended September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Customer A 10 % 16 % * 14 % Customer B * 11 * 12 Customer C 18 25 19 25 Customer D 11 * 11 * Customers accounting for 10% or more of the Company’s accounts receivable were as follows: September 30, 2017 December 31, 2016 Customer A 11 % 12 % Customer B * 11 Customer C 14 17 Customer D 19 17 * Less than 10% Business Combinations The Company accounts for its acquisitions using the acquisition method. 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. 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. Purchased intangible assets consist of identifiable intangible assets, which consisted 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. 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 fees and records a corresponding liability at the gross amount of the liability when the license period begins, the cost of the content is known and the content is accepted and available for streaming. At September 30, 2017, $506,000 of content met these requirements and is recorded in “Prepaid expenses and other current assets”. Recently Issued Accounting Pronouncements Not Yet Adopted In July 2017, the Financial Accounting Standards Board (“FASB”) issued new guidance to address the complexity of the accounting for certain financial instruments with down round features that result in the strike price being reduced on the basis of the pricing of future equity offerings. Under this guidance, when determining the classification of certain financial instruments as liability or equity, a down round feature no longer precludes equity classification when assessing whether the instrument is indexed to an entity’s own stock. The guidance is effective for financial statements issued for fiscal years beginning after December 15, 2018, with early adoption permitted. The Company is evaluating the impact of this new guidance on the consolidated financial statements and the related disclosures. In January 2017, the FASB issued new guidance which eliminates Step 2 from the goodwill impairment test which measures a goodwill impairment loss by comparing the implied fair value of a reporting unit’s goodwill with the carrying amount of that goodwill. Under this guidance, an entity should perform its annual or interim goodwill impairment test by comparing the fair value of the reporting unit with its carrying amount, and should recognize an impairment loss for the amount by which the carrying amount exceeds the reporting unit’s fair value, with the loss not exceeding the total amount of goodwill allocated to that reporting unit. The guidance is effective for financial statements issued for fiscal years beginning after December 15, 2019, with early adoption permitted. The guidance should be applied prospectively. The Company is evaluating the impact of this new guidance on the consolidated financial statements and the related disclosures. In January 2017, the FASB issued new guidance which changes the definition of a business to assist entities with evaluating when a set of transferred assets and activities should be accounted for as an acquisition of a business or group of assets. The guidance requires an entity to evaluate if substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or a group of similar identifiable assets; if so, the set of transferred assets and activities is not a business. The guidance is effective for financial statements issued for fiscal years beginning after December 15, 2017, with early adoption permitted. The guidance should be applied prospectively to any transactions occurring on or after the adoption date. The Company is evaluating the impact of this new guidance on the consolidated financial statements and the related disclosures. In August 2016, the FASB issued new guidance which addresses classification of certain cash receipts and cash payments related to the statement of cash flows. The guidance is effective for financial statements issued for fiscal years beginning after December 15, 2017, with early adoption permitted. The Company is evaluating the impact of this new guidance on the consolidated financial statements and the related disclosures. In February 2016, the FASB issued new guidance related to new accounting and reporting guidelines for leasing arrangements. The guidance requires organizations that lease assets to recognize assets and liabilities on the balance sheet related to the rights and obligations created by those leases, regardless of whether they are classified as finance or operating leases. The guidance is effective for financial statements issued for fiscal years beginning after December 15, 2018, with early adoption permitted. The new standard is to be applied using a modified retrospective approach. The Company is evaluating the impact of this new guidance on the consolidated financial statements and the related disclosures. In January 2016, the FASB issued new guidance related to the accounting for equity investments, financial liabilities under the fair value option, and the presentation and disclosure requirements for financial instruments. The guidance is effective for financial statements issued for fiscal years beginning after December 15, 2018, with early adoption permitted. The Company is evaluating the impact of this new guidance on the consolidated financial statements and the related disclosures. In May 2014, the FASB issued new guidance related to the recognition and reporting of revenue that establishes a comprehensive new revenue recognition model designed to depict the transfer of goods or services to a customer in an amount that reflects the consideration the entity expects to receive in exchange for those goods or services. In August 2015, the FASB deferred the effective date for annual reporting periods beginning after December 15, 2017. In 2016 the FASB issued amendments on this guidance with the same effective date and transition guidance. The Company plans to adopt the new revenue standard in its first quarter of 2018 using the modified retrospective approach, which requires the cumulative impact of initially applying the guidance to be recognized as an adjustment to the Company’s accumulated deficit as of January 1, 2018, the date of adoption. Prior periods will not be retroactively adjusted. To date, the Company has established an implementation team and is in the process of evaluating 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 is continuing to evaluate the potential impact that the implementation of this standard will have on its condensed consolidated financial statements, but has not yet determined whether the effect will be material. However, the Company believes this new standard will impact its 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; • Estimation of variable consideration for content publisher arrangements with revenue share from user subscriptions and media purchases through its platform and the sale of branded channel buttons on its remote controls; and • Expanded disclosures. The Company expects revenue recognition related to players to remain relatively unchanged under the new guidance and is in the process of evaluating the impact on its player arrangements. Fair Value Measurements Level 1 —Quoted prices (unadjusted) in active markets that are accessible at the measurement date for identical assets or 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. Level 3 —Unobservable inputs are used when little or no market data is available. The fair value hierarchy gives the lowest priority to Level 3 inputs. Level 1 liabilities consist of accounts payable, accrued expenses and long-term debt. The carrying amounts of accounts receivable, prepaid expenses, accounts payable and accrued liabilities approximate fair value due to the short-term nature of these items. Based on the borrowing rates currently available to the Company for debt with similar terms, the carrying value of the line of credit and term debt approximate fair value as well. The tables below summarize the Company’s financial instruments’ classification within the fair value hierarchy as follows (in thousands): September 30, 2017 Level 1 Level 2 Level 3 Total Financial liabilities—convertible preferred stock warrant liability $ — $ — $ 52,355 $ 52,355 Total financial liabilities $ — $ — $ 52,355 $ 52,355 December 31, 2016 Level 1 Level 2 Level 3 Total Financial liabilities—convertible preferred stock warrant liability $ — $ — $ 9,990 $ 9,990 Total financial liabilities $ — $ — $ 9,990 $ 9,990 Level 3 instruments consist solely of the Company’s preferred stock warrant liability in which the fair value was measured 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 for periods prior to the IPO 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 following table represents the activity of the fair value of Level 3 instruments (in thousands): September 30, 2017 December 31, 2016 Beginning balance $ 9,990 $ 10,878 Fair value of warrants issued during the period 2,032 — Change in fair value of preferred stock warrant liability 40,333 (888 ) Ending balance $ 52,355 $ 9,990

Business Combinations

Business Combinations	9 Months Ended
	Sep. 30, 2017
Business Combinations [Abstract]
Business Combinations	3. BUSINESS COMBINATIONS 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 $3,500,000. In addition, the Company issued 108,332 shares of its 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 $350,000 of costs related to the acquisition. The preliminary purchase price allocation includes $1,554,000 of goodwill and $2,215,000 of identifiable intangible assets, which primarily consist of developed technology, with an expected useful life of 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.

Consolidated Balance Sheet Comp

Consolidated Balance Sheet Components	9 Months Ended
	Sep. 30, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Consolidated Balance Sheet Components	4. CONSOLIDATED Balance sheet components Accounts Receivable, Net —Accounts receivable, net, consisted of the following (in thousands): September 30, 2017 December 31, 2016 Gross accounts receivable $ 100,059 $ 95,538 Allowance for sales returns (4,377 ) (6,916 ) Allowance for sales incentives (10,499 ) (8,503 ) Other allowances (343 ) (794 ) Total allowances (15,219 ) (16,213 ) Total accounts receivable—net $ 84,840 $ 79,325 Allowance for Sales Returns —Allowance for sales returns consisted of the following activities (in thousands): September 30, 2017 December 31, 2016 Beginning balance $ (6,916 ) $ (9,514 ) Charged to revenue (12,495 ) (20,810 ) Utilization of sales return reserve 15,034 23,408 Ending balance $ (4,377 ) $ (6,916 ) Allowance for Sales Incentives —Allowance for sales incentives consisted of the following activities (in thousands): September 30, 2017 December 31, 2016 Beginning balance $ (8,503 ) $ (7,642 ) Charged to revenue (28,048 ) (36,626 ) Utilization of sales incentive reserve 26,052 35,765 Ending balance $ (10,499 ) $ (8,503 ) Property and Equipment, Net —Property and equipment, net consisted of the following (in thousands): September 30, 2017 December 31, 2016 Computers and equipment $ 10,982 $ 8,787 Leasehold improvements 7,134 4,201 Website and internal-use software 4,384 2,902 Office equipment and furniture 1,824 1,452 Total property and equipment 24,324 17,342 Accumulated depreciation and amortization (11,517 ) (7,814 ) Property and equipment, net $ 12,807 $ 9,528 Depreciation and amortization expense for the three months ended September 30, 2017 and October 1, 2016, was $1,303,000 and $1,351,000, respectively. Depreciation and amortization expense for the nine months ended September 30, 2017 and October 1, 2016, was $3,883,000 and $4,201,000, respectively. Accrued Liabilities —Accrued liabilities consisted of the following (in thousands): September 30, 2017 December 31, 2016 Accrued royalty expense $ 14,549 $ 14,940 Accrued inventory 11,325 4,274 Accrued payroll and related expenses 4,352 5,342 Accrued cost of revenue 9,004 7,264 Accrued payments to content publishers 17,651 8,554 Other accrued expenses 8,617 5,782 Total accrued liabilities $ 65,498 $ 46,156 Deferred Revenue —Deferred revenue consisted of the following (in thousands): September 30, 2017 December 31, 2016 Player, current $ 14,359 $ 13,611 Platform, current 16,463 10,341 Total deferred revenue, current 30,822 23,952 Player, non-current 4,767 5,215 Platform, non-current 34,035 23,869 Total deferred revenue, non-current 38,802 29,084 Total deferred revenue $ 69,624 $ 53,036

Debt

Debt	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Debt	5. DEBT Debt obligations consisted of the following (in thousands): September 30, 2017 December 31, 2016 Term Loan $ 25,000 $ — Line of Credit — 15,000 Total debt obligations 25,000 15,000 Compounding interest due at maturity 255 — Less unamortized debt discount and issuance costs (2,212 ) — Balance 23,043 15,000 Current portion of long-term debt — (15,000 ) Long-term debt less current portion $ 23,043 $ — Loan and Security Agreements In May 2015, the Company amended its Restated 2014 loan and security agreement (“Restated LSA”) with Silicon Valley Bank (“Bank’), extending the agreement to June 30, 2017. The amended Restated LSA provides advances under a revolving line of credit up to $30,000,000 and provides for letters of credit to be issued up to the lessor of the available line of credit, reduced by outstanding advances and drawn but unreimbursed letters of credit, or $5,000,000. 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 and requires the Company to maintain a current ratio (calculated as current assets, divided by current liabilities less deferred revenue), greater than or equal to 1.1. The interest rate on the line of credit was 3.75% as of December 31, 2016. As of December 31, 2016, $15,000,000 under the line of credit was outstanding and letters of credit in the amount of $868,000 were outstanding. As of December 31, 2016, the Company was in compliance with all of the covenants in the amended Restated 2014 LSA. In June 2017, the Company entered into a second amendment to the Restated 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 September 30, 2017, no borrowings under the revolving line of credit were outstanding and letters of credit in the amount of $1,472,000 were outstanding. As of September 30, 2017, the Company was in compliance with all of the covenants in the amended Restated LSA. 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 $40,000,000 with a minimum of $25,000,000 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 $5,000,000 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. In connection with the 2017 Agreement the Company issued 408,648 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 114,933 warrants to purchase Class B common stock that were contingent on future borrowings.

Stockholders' Deficit

Stockholders' Deficit	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Stockholders' Deficit	6. STOCKHOLDERS’ DEFICIT Convertible Preferred Stock — As of September 30, 2017 and December 31, 2016 convertible preferred stock consisted of the following (in thousands, except share and per share data): September 30, 2017 and December 31,2016 Series Price Shares Authorized Shares Outstanding Liquidation Preference A $ 0.36312 23,020,000 23,019,997 $ 8,359 B 0.93808 6,396,071 6,396,068 6,000 C-1 0.54109 9,240,560 9,240,558 5,000 C-2 0.64931 8,950,467 7,700,466 5,000 D 2.37840 4,685,755 4,204,505 10,000 E 4.35679 11,160,733 11,074,655 48,250 F 5.43396 11,041,671 11,041,667 60,000 G 7.79730 3,206,239 3,206,234 25,000 H 9.17340 6,666,667 4,959,988 45,500 Total 84,368,163 80,844,138 $ 213,109 Upon the closing of the Company’s IPO, all outstanding shares of its convertible preferred stock automatically converted into 80,844,138 shares of Class B common stock on a one-to-one basis. (Note 12) Common Stock — At September 30, 2017 there were 1,000,000,000 shares of Class A common stock and 150,000,000 shares of Class B common stock, par value $0.0001, authorized. There were no shares of Class A common stock and 5,637,785 shares of Class B common stock issued and outstanding at September 30, 2017. At December 31, 2016 there were 122,000,000 shares of common stock, par $0.0001, authorized and 4,818,812 shares issued and outstanding. The Company had reserved shares of common stock for issuance as follows: September 30, 2017 December 31, 2016 Conversion of: Series A convertible preferred stock 23,019,997 23,019,997 Series B convertible preferred stock 6,396,068 6,396,068 Series C-1 convertible preferred stock 9,240,558 9,240,558 Series C-2 convertible preferred stock 7,700,466 7,700,466 Series C-2 convertible preferred stock warrants 1,250,000 1,250,000 Series D convertible preferred stock 4,204,505 4,204,505 Series D convertible preferred stock warrants 481,246 481,246 Series E convertible preferred stock 11,074,655 11,074,655 Series E convertible preferred stock warrants 86,072 86,072 Series F convertible preferred stock 11,041,667 11,041,667 Series G convertible preferred stock 3,206,234 3,206,234 Series H convertible preferred stock 4,959,988 4,959,988 Series H convertible preferred stock warrants 408,648 — Conversion of common stock warrants — 375,000 Common stock options issued under stock option plan 27,326,277 22,334,508 Common stock options available for grant under stock option plan 1,221,824 409,582 Total 111,618,205 105,780,546 Stock Option Plan —As of September 30, 2017 and December 31, 2016 the Company had reserved for issuance 28,548,101 and 22,744,090 shares of common stock, respectively, under the Company’s 2008 Equity Incentive Plan (the “2008 Plan”). Options granted under the 2008 Plan must be 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 must be 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”). (Note 12). No further shares would be issued under the 2008 Plan at the time the 2017 Plan became effective. Activity under the Company’s equity incentive plans is as follows: Shares Available for Grant Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Life (Years) Weighted Average Grant Date Fair Value Per Share Balance, December 31, 2016 409,582 22,334,508 3.66 6.6 — Increase authorization 6,250,000 — — — Granted (6,013,312 ) 6,013,312 7.47 — $ 3.48 Exercised — (445,995 ) 3.91 — — Forfeited and expired 575,554 (575,554 ) 5.49 — — Balance, September 30, 2017 1,221,824 27,326,271 4.46 6.7 — The aggregate intrinsic value of the shares vested and exercisable at September 30, 2017 was $354,849,000. Stock-Based Compensation —The fair value of options granted under the 2008 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. 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. Fair Value of Common Stock —Given the absence of a public trading market at the date of the grant, the Company’s board of directors consider numerous objective and subjective factors to determine the fair value of the common stock at each grant date. These factors include, but are not limited to (i) independent contemporaneous third-party valuations of the common stock; (ii) the prices for the preferred stock sold to outside investors; (iii) the rights and preferences of convertible preferred stock relative to the common stock; (iv) the lack of marketability of the common stock; (v) developments in the business; and (vi) the likelihood of achieving a liquidity event, such as an IPO or sale of the Company, given prevailing market conditions. The Company uses the straight-line method for expense recognition. The assumptions used to value stock-based awards granted are as follows: Three Months Ended Nine Months Ended September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Dividend rate $ — — — — Expected term (in years) 5.3 - 6.5 — 5.3 - 6.5 5.3 - 6.5 Risk-free interest rate 1.84 - 2.03% — 1.84% - 2.25% 1.32% - 1.50% Expected volatility 39% - 43% — 39% - 44% 44% - 46% Fair value of common stock $ 8.82 — $5.70 - $8.82 $ 6.60 The total intrinsic value of options exercised during the nine months ended September 30, 2017 and October 1, 2016, was $1,510,000 and $350,000, respectively. As of September 30, 2017, the Company had $33,750,000 of unrecognized stock compensation expense related to unvested stock options that is expected to be recognized over a weighted-average period of approximately 2.8 years. As a result of the Company’s Black-Scholes option-valuation fair value calculations and the Company’s use of the straight-line vesting attribution method, the Company recognized employee stock-based compensation expense as follows (in thousands): Three Months Ended Nine Months Ended September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Cost of player revenue $ 25 $ 30 $ 99 $ 88 Cost of platform revenue 18 63 58 165 Research and development 1,197 651 3,078 1,924 Sales and marketing 808 580 2,099 1,737 General and administrative 876 687 2,183 2,102 Total $ 2,924 $ 2,011 $ 7,517 $ 6,016 Common Stock Warrants —In July 2017 the Company issued 357,283 shares of common stock upon expiration of 375,000 common stock warrants issued in 2009. There were no common stock warrants outstanding at September 30, 2017. Preferred Stock Warrants — Outstanding preferred stock warrants were as follows: Series Number Outstanding September 30, 2017 Number Outstanding December 31, 2016 Issuance Date Exercise Price Original Term C-2 1,250,000 1,250,000 July 13, 2011 $ 0.64931 10 years D 249,999 249,999 October 17, 2011 2.37840 10 years D 168,180 168,180 March 12, 2012 2.37840 10 years D 63,067 63,067 April 27, 2012 2.37840 10 years E 86,072 86,072 April 27, 2012 3.48546 10 years H 408,648 — June 9, 2017 9.17340 10 years Total 2,225,966 1,817,318 Upon the closing of the Company’s IPO, all outstanding convertible preferred stock warrants automatically converted to Class B common stock warrants. (Note 12) The fair value of the preferred stock warrants has been recorded as a liability as of September 30, 2017 and December 31, 2016. The fair value of the preferred stock warrants is remeasured as of each balance sheet date using the Black-Scholes option-pricing model. Changes in the fair value of the preferred stock warrants during the year are recognized in the consolidated statements of operations. The assumptions used to value the preferred stock warrants using the Black-Scholes model are as follows: September 30, 2017 December 31, 2016 Dividends $ — $ — Expected term (in years) 3.0-9.7 3.2-3.9 Risk-free interest rate 1.5%—2.3% 0.7%—1.6% Volatility 43.5%—50.7% 46.2%—47.8%

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2017
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	7. 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 (“UK”), and China, with expiration dates from May 2017 to September 2024. Rent expense for the three months ended September 30, 2017 and October 1, 2016 was $1,716,000 and $1,122,000 respectively. Rent expense for the nine months ended September 30, 2017 and October 1, 2016 was $4,805,000 and $3,505,000 (excluding amounts related to the loss from the exit of the former headquarters facilities), 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 a contract that is noncancelable. As of September 30, 2017 the Company had $87,151,000 $ purchase commitments for inventory issued to this vendor. The Company records a liability for noncancelable purchase commitments in excess of its future demand forecasts. The Company recorded $1,366,000 and $2,040,000 for these purchase commitments in “Accrued liabilities” at September 30, 2017 and December 31, 2016. 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 September 30, 2017, the Company had $506,000 of obligations recorded in “Accrued liabilities” for license purchase commitments and $1,611,000 of obligations that are not reflected on the financial statements as they do not yet meet the criteria for asset recognition. There were no content license agreements at December 31, 2016. Letter of Credit —As of September 30, 2017 and December 31, 2016 the Company had irrevocable letters of credit outstanding in the amount of $1,472,000 and $868,000 for the benefit of a landlord related to noncancelable facilities leases. The letters of credit have expiration dates from January 2018 to August 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 manufacturers 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 September 30, 2017 and December 31, 2016 and 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.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	8. INCOME TAXES The Company is subject to income tax in the U.S. as well as other tax jurisdictions in which it conducts business. Earnings from non-U.S. activities are subject to local country income tax. The Company does not provide for federal income taxes on the undistributed earnings of its foreign subsidiaries as such earnings are expected to be reinvested indefinitely. The Company recorded an income tax expense of $144,000 and $103,000 for the nine months ended September 30, 2017 and October 1, 2016, respectively, related to foreign income taxes and state minimum taxes. Based on the available objective evidence during the nine months ended September 30, 2017, the Company believes it is more likely than not that the tax benefits of the U.S. losses incurred during the nine months ended September 30, 2017 may not be realized. Accordingly, the Company recorded a full valuation allowance against the tax benefits of the U.S. losses incurred during the nine months ended September 30, 2017. The primary difference between the effective tax rate and the local statutory tax rate relates to the valuation allowance on the Company’s U.S. losses.

Related-Party Transactions

Related-Party Transactions	9 Months Ended
	Sep. 30, 2017
Related Party Transactions [Abstract]
Related-Party Transactions	9. RELATED-PARTY TRANSACTIONS The Company has agreements with one of the Company’s strategic investors. In the three months ended September 30, 2017 and October 1, 2016, the Company recorded $153,000 and $121,000 of revenue from sales to this investor. In the nine months ended September 30, 2017 and October 1, 2016, the Company recorded $243,000 and $627,000 of revenue from sales to this investor. The Company had receivable balances of $153,000 and $148,000 related to these sales at September 30, 2017 and December 31, 2016, respectively.

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Net Loss Per Share	10. 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 nine months ended September 30, 2017 and October 1, 2016 and the three months ended September 30, 2017 and October 1, 2016, 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 (in thousands, except share and per share data): Three Months Ended Nine Months Ended September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Numerator: Net loss allocable to common stockholders $ (46,235 ) $ (12,743 ) $ (70,450 ) $ (45,985 ) Denominator: Weighted-average shares used in computing net loss per share, basic and diluted 5,259,796 4,784,170 4,998,727 4,724,767 Net loss per share, basic and diluted $ (8.79 ) $ (2.66 ) $ (14.09 ) $ (9.73 ) 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: September 30, 2017 October 1, 2016 Options to purchase common stock 27,326,277 20,628,248 Unvested shares of common stock issued upon early exercise of stock options 51,686 4,566 Warrants to purchase common stock - 375,000 Warrants to purchase convertible preferred stock 2,225,966 1,817,320 Convertible preferred stock 80,844,138 80,844,138 Total 110,448,067 103,669,272

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Segment Information	11. 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’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 remote controls. The accounting policies for the segments are the same as those described in our Prospectus. 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 player segment revenue, net, were as follows: Three Months Ended Nine Months Ended September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Customer A 19 % 22 % 15 % 19 % Customer B * 10 10 11 Customer C 32 33 32 33 Customers accounting for 10% or more of platform segment revenue were as follows: Three Months Ended Nine Months Ended September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Customer 1 *% 14 % *% 17 % Customer 3 14 12 13 * * Less than 10% Substantially all Company assets were held in the United States and were attributable to the operations in the United States as of September 30, 2017 and December 31, 2016. Revenue in international markets was less than 10% in each of the periods presented.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2017
Subsequent Events [Abstract]
Subsequent Events	12. SUBSEQUENT EVENTS IPO — On October 2, 2017, the Company completed its IPO of Class A common stock, in which it sold 10,350,000 shares, including 1,350,000 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 $134,757,000, after deducting underwriting discounts and commissions of $10,143,000. Additionally, offering costs incurred by the Company totaled approximately $4,000,000. Upon the closing of the Company’s IPO, all outstanding shares of its convertible preferred stock automatically converted into 80,844,138 shares of Class B common stock and all outstanding convertible preferred stock warrants automatically converted to Class B common stock warrants on a one-to-one basis. In connection with the IPO, the Company amended and restated its Certificate of Incorporation to change the authorized capital stock to 1,000,000,000 shares of Class A common stock, 150,000,000 shares of Class B common stock, and 10,000,000 shares of preferred stock, all with a par value of $0.0001 per share. The Consolidated Financial Statements as of September 30, 2017, including share and per share amounts, do not give effect to the IPO, conversion of the convertible preferred stock, or conversion of the preferred stock warrants as the IPO and such conversions were completed subsequent to September 30, 2017. Debt Extinguishment — In October 2017, the Company repaid all outstanding advances, accrued interest and associated fees due under the 2017 Agreement with the Bank and terminated the agreement. The repayment was treated as a debt extinguishment and, as a result, the Company will record a loss on extinguishment of debt of $2,338,000. In connection with the repayment, the Company cancelled 114,933 warrants to purchase Class B common stock that were contingent on future borrowings. Class B Common Stock Warrants — In October 2017, the Company issued 956,511 shares of Class B common stock upon net exercise of 1,043,009 Class B common stock warrants issued in connection with various debt agreements entered into from 2011 to 2017. These common stock warrants had converted from convertible preferred stock warrants at the close of the IPO.

Summary of Significant Accoun18

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Basis of Presentation and Use of Estimates	Basis of Presentation and Use of Estimates The condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (the “SEC”) regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements contained in our final prospectus filed pursuant to Rule 424(b) under the Securities Act of 1933, as amended, with the SEC on September 28, 2017 (the “Prospectus”). There have been no material changes in the Company’s significant accounting policies from those that were disclosed in the Prospectus, except as noted below.
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 the 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, the fair value of assets and liabilities acquired in business combinations and the fair value of the Company’s preferred stock and common stock. 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. To the extent that there are material differences between these estimates and actual results, the Company’s financial condition or operating results will be affected.
Principles of Consolidation	Principles of Consolidation The condensed consolidated financial statements have been prepared in accordance with U.S. GAAP and includes the accounts of the Company and its wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated in consolidation.
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 condensed consolidated financial statements.
Concentrations	Concentrations Customers accounting for 10% or more of the Company’s net revenue were as follows: Three Months Ended Nine Months Ended September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Customer A 10 % 16 % * 14 % Customer B * 11 * 12 Customer C 18 25 19 25 Customer D 11 * 11 * Customers accounting for 10% or more of the Company’s accounts receivable were as follows: September 30, 2017 December 31, 2016 Customer A 11 % 12 % Customer B * 11 Customer C 14 17 Customer D 19 17 * Less than 10%
Business Combinations	Business Combinations The Company accounts for its acquisitions using the acquisition method. 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. 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. Purchased intangible assets consist of identifiable intangible assets, which consisted 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.
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 fees and records a corresponding liability at the gross amount of the liability when the license period begins, the cost of the content is known and the content is accepted and available for streaming. At September 30, 2017, $506,000 of content met these requirements and is recorded in “Prepaid expenses and other current assets”.
Recently Issued Accounting Pronouncements Not Yet Adopted	Recently Issued Accounting Pronouncements Not Yet Adopted In July 2017, the Financial Accounting Standards Board (“FASB”) issued new guidance to address the complexity of the accounting for certain financial instruments with down round features that result in the strike price being reduced on the basis of the pricing of future equity offerings. Under this guidance, when determining the classification of certain financial instruments as liability or equity, a down round feature no longer precludes equity classification when assessing whether the instrument is indexed to an entity’s own stock. The guidance is effective for financial statements issued for fiscal years beginning after December 15, 2018, with early adoption permitted. The Company is evaluating the impact of this new guidance on the consolidated financial statements and the related disclosures. In January 2017, the FASB issued new guidance which eliminates Step 2 from the goodwill impairment test which measures a goodwill impairment loss by comparing the implied fair value of a reporting unit’s goodwill with the carrying amount of that goodwill. Under this guidance, an entity should perform its annual or interim goodwill impairment test by comparing the fair value of the reporting unit with its carrying amount, and should recognize an impairment loss for the amount by which the carrying amount exceeds the reporting unit’s fair value, with the loss not exceeding the total amount of goodwill allocated to that reporting unit. The guidance is effective for financial statements issued for fiscal years beginning after December 15, 2019, with early adoption permitted. The guidance should be applied prospectively. The Company is evaluating the impact of this new guidance on the consolidated financial statements and the related disclosures. In January 2017, the FASB issued new guidance which changes the definition of a business to assist entities with evaluating when a set of transferred assets and activities should be accounted for as an acquisition of a business or group of assets. The guidance requires an entity to evaluate if substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or a group of similar identifiable assets; if so, the set of transferred assets and activities is not a business. The guidance is effective for financial statements issued for fiscal years beginning after December 15, 2017, with early adoption permitted. The guidance should be applied prospectively to any transactions occurring on or after the adoption date. The Company is evaluating the impact of this new guidance on the consolidated financial statements and the related disclosures. In August 2016, the FASB issued new guidance which addresses classification of certain cash receipts and cash payments related to the statement of cash flows. The guidance is effective for financial statements issued for fiscal years beginning after December 15, 2017, with early adoption permitted. The Company is evaluating the impact of this new guidance on the consolidated financial statements and the related disclosures. In February 2016, the FASB issued new guidance related to new accounting and reporting guidelines for leasing arrangements. The guidance requires organizations that lease assets to recognize assets and liabilities on the balance sheet related to the rights and obligations created by those leases, regardless of whether they are classified as finance or operating leases. The guidance is effective for financial statements issued for fiscal years beginning after December 15, 2018, with early adoption permitted. The new standard is to be applied using a modified retrospective approach. The Company is evaluating the impact of this new guidance on the consolidated financial statements and the related disclosures. In January 2016, the FASB issued new guidance related to the accounting for equity investments, financial liabilities under the fair value option, and the presentation and disclosure requirements for financial instruments. The guidance is effective for financial statements issued for fiscal years beginning after December 15, 2018, with early adoption permitted. The Company is evaluating the impact of this new guidance on the consolidated financial statements and the related disclosures. In May 2014, the FASB issued new guidance related to the recognition and reporting of revenue that establishes a comprehensive new revenue recognition model designed to depict the transfer of goods or services to a customer in an amount that reflects the consideration the entity expects to receive in exchange for those goods or services. In August 2015, the FASB deferred the effective date for annual reporting periods beginning after December 15, 2017. In 2016 the FASB issued amendments on this guidance with the same effective date and transition guidance. The Company plans to adopt the new revenue standard in its first quarter of 2018 using the modified retrospective approach, which requires the cumulative impact of initially applying the guidance to be recognized as an adjustment to the Company’s accumulated deficit as of January 1, 2018, the date of adoption. Prior periods will not be retroactively adjusted. To date, the Company has established an implementation team and is in the process of evaluating 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 is continuing to evaluate the potential impact that the implementation of this standard will have on its condensed consolidated financial statements, but has not yet determined whether the effect will be material. However, the Company believes this new standard will impact its 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; • Estimation of variable consideration for content publisher arrangements with revenue share from user subscriptions and media purchases through its platform and the sale of branded channel buttons on its remote controls; and • Expanded disclosures. The Company expects revenue recognition related to players to remain relatively unchanged under the new guidance and is in the process of evaluating the impact on its player arrangements.
Fair Value Measurements	Fair Value Measurements Level 1 —Quoted prices (unadjusted) in active markets that are accessible at the measurement date for identical assets or 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. Level 3 —Unobservable inputs are used when little or no market data is available. The fair value hierarchy gives the lowest priority to Level 3 inputs. Level 1 liabilities consist of accounts payable, accrued expenses and long-term debt. The carrying amounts of accounts receivable, prepaid expenses, accounts payable and accrued liabilities approximate fair value due to the short-term nature of these items. Based on the borrowing rates currently available to the Company for debt with similar terms, the carrying value of the line of credit and term debt approximate fair value as well. The tables below summarize the Company’s financial instruments’ classification within the fair value hierarchy as follows (in thousands): September 30, 2017 Level 1 Level 2 Level 3 Total Financial liabilities—convertible preferred stock warrant liability $ — $ — $ 52,355 $ 52,355 Total financial liabilities $ — $ — $ 52,355 $ 52,355 December 31, 2016 Level 1 Level 2 Level 3 Total Financial liabilities—convertible preferred stock warrant liability $ — $ — $ 9,990 $ 9,990 Total financial liabilities $ — $ — $ 9,990 $ 9,990 Level 3 instruments consist solely of the Company’s preferred stock warrant liability in which the fair value was measured 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 for periods prior to the IPO 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 following table represents the activity of the fair value of Level 3 instruments (in thousands): September 30, 2017 December 31, 2016 Beginning balance $ 9,990 $ 10,878 Fair value of warrants issued during the period 2,032 — Change in fair value of preferred stock warrant liability 40,333 (888 ) Ending balance $ 52,355 $ 9,990

Summary of Significant Accoun19

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2017
Summary of Company’s Financial Instruments Classification Within Fair Value Hierarchy	The tables below summarize the Company’s financial instruments’ classification within the fair value hierarchy as follows (in thousands): September 30, 2017 Level 1 Level 2 Level 3 Total Financial liabilities—convertible preferred stock warrant liability $ — $ — $ 52,355 $ 52,355 Total financial liabilities $ — $ — $ 52,355 $ 52,355 December 31, 2016 Level 1 Level 2 Level 3 Total Financial liabilities—convertible preferred stock warrant liability $ — $ — $ 9,990 $ 9,990 Total financial liabilities $ — $ — $ 9,990 $ 9,990
Schedule of Fair Value of Level 3 Instruments	The following table represents the activity of the fair value of Level 3 instruments (in thousands): September 30, 2017 December 31, 2016 Beginning balance $ 9,990 $ 10,878 Fair value of warrants issued during the period 2,032 — Change in fair value of preferred stock warrant liability 40,333 (888 ) Ending balance $ 52,355 $ 9,990
Net Revenue
Schedules of Customer Concentration by Risk Factor	Customers accounting for 10% or more of the Company’s net revenue were as follows: Three Months Ended Nine Months Ended September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Customer A 10 % 16 % * 14 % Customer B * 11 * 12 Customer C 18 25 19 25 Customer D 11 * 11 *
Accounts Receivable
Schedules of Customer Concentration by Risk Factor	Customers accounting for 10% or more of the Company’s accounts receivable were as follows: September 30, 2017 December 31, 2016 Customer A 11 % 12 % Customer B * 11 Customer C 14 17 Customer D 19 17 * Less than 10%

Consolidated Balance Sheet Co20

Consolidated Balance Sheet Components (Tables)	9 Months Ended
	Sep. 30, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Schedule of Accounts Receivable, Net	Accounts receivable, net, consisted of the following (in thousands): September 30, 2017 December 31, 2016 Gross accounts receivable $ 100,059 $ 95,538 Allowance for sales returns (4,377 ) (6,916 ) Allowance for sales incentives (10,499 ) (8,503 ) Other allowances (343 ) (794 ) Total allowances (15,219 ) (16,213 ) Total accounts receivable—net $ 84,840 $ 79,325
Schedule of Allowance for Sales Returns	Allowance for sales returns consisted of the following activities (in thousands): September 30, 2017 December 31, 2016 Beginning balance $ (6,916 ) $ (9,514 ) Charged to revenue (12,495 ) (20,810 ) Utilization of sales return reserve 15,034 23,408 Ending balance $ (4,377 ) $ (6,916 )
Schedule of Allowance for Sales Incentives	Allowance for sales incentives consisted of the following activities (in thousands): September 30, 2017 December 31, 2016 Beginning balance $ (8,503 ) $ (7,642 ) Charged to revenue (28,048 ) (36,626 ) Utilization of sales incentive reserve 26,052 35,765 Ending balance $ (10,499 ) $ (8,503 )
Schedule of Property and Equipment, Net	Property and equipment, net consisted of the following (in thousands): September 30, 2017 December 31, 2016 Computers and equipment $ 10,982 $ 8,787 Leasehold improvements 7,134 4,201 Website and internal-use software 4,384 2,902 Office equipment and furniture 1,824 1,452 Total property and equipment 24,324 17,342 Accumulated depreciation and amortization (11,517 ) (7,814 ) Property and equipment, net $ 12,807 $ 9,528
Schedule of Accrued Liabilities	Accrued liabilities consisted of the following (in thousands): September 30, 2017 December 31, 2016 Accrued royalty expense $ 14,549 $ 14,940 Accrued inventory 11,325 4,274 Accrued payroll and related expenses 4,352 5,342 Accrued cost of revenue 9,004 7,264 Accrued payments to content publishers 17,651 8,554 Other accrued expenses 8,617 5,782 Total accrued liabilities $ 65,498 $ 46,156
Schedule of Deferred Revenue	Deferred revenue consisted of the following (in thousands): September 30, 2017 December 31, 2016 Player, current $ 14,359 $ 13,611 Platform, current 16,463 10,341 Total deferred revenue, current 30,822 23,952 Player, non-current 4,767 5,215 Platform, non-current 34,035 23,869 Total deferred revenue, non-current 38,802 29,084 Total deferred revenue $ 69,624 $ 53,036

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Schedule of Debt Obligations	Debt obligations consisted of the following (in thousands): September 30, 2017 December 31, 2016 Term Loan $ 25,000 $ — Line of Credit — 15,000 Total debt obligations 25,000 15,000 Compounding interest due at maturity 255 — Less unamortized debt discount and issuance costs (2,212 ) — Balance 23,043 15,000 Current portion of long-term debt — (15,000 ) Long-term debt less current portion $ 23,043 $ —

Stockholders' Deficit (Tables)

Stockholders' Deficit (Tables)	9 Months Ended
	Sep. 30, 2017
Schedule of Activity Under Equity Incentive Plan	Activity under the Company’s equity incentive plans is as follows: Shares Available for Grant Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Life (Years) Weighted Average Grant Date Fair Value Per Share Balance, December 31, 2016 409,582 22,334,508 3.66 6.6 — Increase authorization 6,250,000 — — — Granted (6,013,312 ) 6,013,312 7.47 — $ 3.48 Exercised — (445,995 ) 3.91 — — Forfeited and expired 575,554 (575,554 ) 5.49 — — Balance, September 30, 2017 1,221,824 27,326,271 4.46 6.7 —
Schedule of Convertible Preferred Stock	Convertible Preferred Stock — As of September 30, 2017 and December 31, 2016 convertible preferred stock consisted of the following (in thousands, except share and per share data): September 30, 2017 and December 31,2016 Series Price Shares Authorized Shares Outstanding Liquidation Preference A $ 0.36312 23,020,000 23,019,997 $ 8,359 B 0.93808 6,396,071 6,396,068 6,000 C-1 0.54109 9,240,560 9,240,558 5,000 C-2 0.64931 8,950,467 7,700,466 5,000 D 2.37840 4,685,755 4,204,505 10,000 E 4.35679 11,160,733 11,074,655 48,250 F 5.43396 11,041,671 11,041,667 60,000 G 7.79730 3,206,239 3,206,234 25,000 H 9.17340 6,666,667 4,959,988 45,500 Total 84,368,163 80,844,138 $ 213,109
Schedule of Reserved Shares of Common Stock for Issuance	The Company had reserved shares of common stock for issuance as follows: September 30, 2017 December 31, 2016 Conversion of: Series A convertible preferred stock 23,019,997 23,019,997 Series B convertible preferred stock 6,396,068 6,396,068 Series C-1 convertible preferred stock 9,240,558 9,240,558 Series C-2 convertible preferred stock 7,700,466 7,700,466 Series C-2 convertible preferred stock warrants 1,250,000 1,250,000 Series D convertible preferred stock 4,204,505 4,204,505 Series D convertible preferred stock warrants 481,246 481,246 Series E convertible preferred stock 11,074,655 11,074,655 Series E convertible preferred stock warrants 86,072 86,072 Series F convertible preferred stock 11,041,667 11,041,667 Series G convertible preferred stock 3,206,234 3,206,234 Series H convertible preferred stock 4,959,988 4,959,988 Series H convertible preferred stock warrants 408,648 — Conversion of common stock warrants — 375,000 Common stock options issued under stock option plan 27,326,277 22,334,508 Common stock options available for grant under stock option plan 1,221,824 409,582 Total 111,618,205 105,780,546
Summary of Assumptions Used to Value Stock-Based Awards Granted	The assumptions used to value stock-based awards granted are as follows: Three Months Ended Nine Months Ended September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Dividend rate $ — — — — Expected term (in years) 5.3 - 6.5 — 5.3 - 6.5 5.3 - 6.5 Risk-free interest rate 1.84 - 2.03% — 1.84% - 2.25% 1.32% - 1.50% Expected volatility 39% - 43% — 39% - 44% 44% - 46% Fair value of common stock $ 8.82 — $5.70 - $8.82 $ 6.60
Summary of Recognized Employee Stock-Based Compensation Expense	As a result of the Company’s Black-Scholes option-valuation fair value calculations and the Company’s use of the straight-line vesting attribution method, the Company recognized employee stock-based compensation expense as follows (in thousands): Three Months Ended Nine Months Ended September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Cost of player revenue $ 25 $ 30 $ 99 $ 88 Cost of platform revenue 18 63 58 165 Research and development 1,197 651 3,078 1,924 Sales and marketing 808 580 2,099 1,737 General and administrative 876 687 2,183 2,102 Total $ 2,924 $ 2,011 $ 7,517 $ 6,016
Preferred Stock Warrants
Summary of Assumptions Used to Value Stock-Based Awards Granted	The assumptions used to value the preferred stock warrants using the Black-Scholes model are as follows: September 30, 2017 December 31, 2016 Dividends $ — $ — Expected term (in years) 3.0-9.7 3.2-3.9 Risk-free interest rate 1.5%—2.3% 0.7%—1.6% Volatility 43.5%—50.7% 46.2%—47.8%
Schedule of Convertible Preferred Stock Warrants	Outstanding preferred stock warrants were as follows: Series Number Outstanding September 30, 2017 Number Outstanding December 31, 2016 Issuance Date Exercise Price Original Term C-2 1,250,000 1,250,000 July 13, 2011 $ 0.64931 10 years D 249,999 249,999 October 17, 2011 2.37840 10 years D 168,180 168,180 March 12, 2012 2.37840 10 years D 63,067 63,067 April 27, 2012 2.37840 10 years E 86,072 86,072 April 27, 2012 3.48546 10 years H 408,648 — June 9, 2017 9.17340 10 years Total 2,225,966 1,817,318

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 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 (in thousands, except share and per share data): Three Months Ended Nine Months Ended September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Numerator: Net loss allocable to common stockholders $ (46,235 ) $ (12,743 ) $ (70,450 ) $ (45,985 ) Denominator: Weighted-average shares used in computing net loss per share, basic and diluted 5,259,796 4,784,170 4,998,727 4,724,767 Net loss per share, basic and diluted $ (8.79 ) $ (2.66 ) $ (14.09 ) $ (9.73 )
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: September 30, 2017 October 1, 2016 Options to purchase common stock 27,326,277 20,628,248 Unvested shares of common stock issued upon early exercise of stock options 51,686 4,566 Warrants to purchase common stock - 375,000 Warrants to purchase convertible preferred stock 2,225,966 1,817,320 Convertible preferred stock 80,844,138 80,844,138 Total 110,448,067 103,669,272

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2017
Player
Entity Wide Revenue Major Customer [Line Items]
Schedule of Customer Accounting for 10% or More of Segment Revenue	Customers accounting for 10% or more of player segment revenue, net, were as follows: Three Months Ended Nine Months Ended September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Customer A 19 % 22 % 15 % 19 % Customer B * 10 10 11 Customer C 32 33 32 33
Platform
Entity Wide Revenue Major Customer [Line Items]
Schedule of Customer Accounting for 10% or More of Segment Revenue	Customers accounting for 10% or more of platform segment revenue were as follows: Three Months Ended Nine Months Ended September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Customer 1 *% 14 % *% 17 % Customer 3 14 12 13 * * Less than 10%

The Company - Additional Inform

The Company - Additional Information (Details)	Oct. 02, 2017USD ($)$ / sharesshares	Sep. 30, 2017segment
Entity Wide Revenue Major Customer [Line Items]
Conversion date		Feb. 1, 2008
Number of reportable segments operates | segment		2
Subsequent Event | Initial Public Offering | Class B Common Stock Warrants
Entity Wide Revenue Major Customer [Line Items]
Warrants conversion ratio	100.00%
Subsequent Event | Initial Public Offering | Class A Common Stock
Entity Wide Revenue Major Customer [Line Items]
Initial public offering completed date	Oct. 2, 2017
Number of shares sold | shares	10,350,000
Share sold price per share | $ / shares	$ 14
Net proceeds from shares sold | $	$ 134,757,000
Underwriting discounts and commissions | $	10,143,000
Offering costs incurred | $	$ 4,000,000
Subsequent Event | Initial Public Offering | Class B Common Stock
Entity Wide Revenue Major Customer [Line Items]
Convertible preferred stock, Shares converted | shares	80,844,138
Stock conversion ratio	100.00%
Subsequent Event | Over-Allotment Option | Class A Common Stock
Entity Wide Revenue Major Customer [Line Items]
Number of shares sold | shares	1,350,000

Summary of Significant Accoun26

Summary of Significant Accounting Policies - Schedules of Customer Concentration by Risk Factor (Details) - Customer Concentration Risk	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016	Dec. 31, 2016
Net Revenue | Customer A
Concentration Risk [Line Items]
Concentration risk	10.00%	16.00%		14.00%
Net Revenue | Customer B
Concentration Risk [Line Items]
Concentration risk		11.00%		12.00%
Net Revenue | Customer C
Concentration Risk [Line Items]
Concentration risk	18.00%	25.00%	19.00%	25.00%
Net Revenue | Customer D
Concentration Risk [Line Items]
Concentration risk	11.00%		11.00%
Accounts Receivable | Customer A
Concentration Risk [Line Items]
Concentration risk			11.00%		12.00%
Accounts Receivable | Customer B
Concentration Risk [Line Items]
Concentration risk					11.00%
Accounts Receivable | Customer C
Concentration Risk [Line Items]
Concentration risk			14.00%		17.00%
Accounts Receivable | Customer D
Concentration Risk [Line Items]
Concentration risk			19.00%		17.00%

Summary of Significant Accoun27

Summary of Significant Accounting Policies - Additional Information (Details) $ in Thousands	Sep. 30, 2017USD ($)
Licenses | Prepaid Expenses and Other Current Assets
Finite Lived Intangible Assets [Line Items]
Content assets	$ 506

Summary of Significant Accoun28

Summary of Significant Accounting Policies - Summary of Company's Financial Instruments Classification Within Fair Value Hierarchy (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total financial liabilities	$ 52,355	$ 9,990
Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total financial liabilities	52,355	9,990
Convertible Preferred Stock Warrant Liability
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total financial liabilities	52,355	9,990
Convertible Preferred Stock Warrant Liability | Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total financial liabilities	$ 52,355	$ 9,990

Summary of Significant Accoun29

Summary of Significant Accounting Policies - Schedule of Fair Value of Level 3 Instruments (Details) - Convertible Preferred Stock Warrant Liability - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Fair Value Instruments Classified In Shareholders Equity Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 9,990	$ 10,878
Fair value of warrants issued during the period	2,032
Change in fair value of preferred stock warrant liability	40,333	(888)
Ending balance	$ 52,355	$ 9,990

Business Combinations - Additio

Business Combinations - Additional Information (Details) $ in Thousands	Sep. 06, 2017USD ($)Foundershares	Sep. 30, 2017USD ($)
Business Acquisition [Line Items]
Goodwill		$ 1,554
Denmark
Business Acquisition [Line Items]
Date of acquisition	Sep. 6, 2017
Aggregate purchase price	$ 3,500
Shares of common stock issued | shares	108,332
Number of founders who received shares | Founder	2
Acquisition related cost	$ 350
Repurchase period for shares issued under business acquisition	3 years
Goodwill	$ 1,554
Identifiable intangible assets acquired	$ 2,215
Identifiable intangible assets, expected useful life	4 years

Consolidated Balance Sheet Co31

Consolidated Balance Sheet Components - Schedule of Accounts Receivable, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Dec. 31, 2015
Valuation And Qualifying Accounts Disclosure [Line Items]
Gross accounts receivable	$ 100,059	$ 95,538
Allowance for accounts receivable	(15,219)	(16,213)
Total accounts receivable—net	84,840	79,325
Allowance for Sales Returns
Valuation And Qualifying Accounts Disclosure [Line Items]
Allowance for accounts receivable	(4,377)	(6,916)	$ (9,514)
Allowance for Sales Incentives
Valuation And Qualifying Accounts Disclosure [Line Items]
Allowance for accounts receivable	(10,499)	(8,503)	$ (7,642)
Other Allowances
Valuation And Qualifying Accounts Disclosure [Line Items]
Allowance for accounts receivable	$ (343)	$ (794)

Consolidated Balance Sheet Co32

Consolidated Balance Sheet Components - Schedule of Allowance for Sales Returns (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Valuation And Qualifying Accounts Disclosure [Line Items]
Beginning balance	$ (16,213)
Ending balance	(15,219)	$ (16,213)
Allowance for Sales Returns
Valuation And Qualifying Accounts Disclosure [Line Items]
Beginning balance	(6,916)	(9,514)
Charged to revenue	(12,495)	(20,810)
Utilization of sales return/incentive reserve	15,034	23,408
Ending balance	$ (4,377)	$ (6,916)

Consolidated Balance Sheet Co33

Consolidated Balance Sheet Components - Schedule of Allowance for Sales Incentives (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Valuation And Qualifying Accounts Disclosure [Line Items]
Beginning balance	$ (16,213)
Ending balance	(15,219)	$ (16,213)
Allowance for Sales Incentives
Valuation And Qualifying Accounts Disclosure [Line Items]
Beginning balance	(8,503)	(7,642)
Charged to revenue	(28,048)	(36,626)
Utilization of sales return/incentive reserve	26,052	35,765
Ending balance	$ (10,499)	$ (8,503)

Consolidated Balance Sheet Co34

Consolidated Balance Sheet Components - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Property Plant And Equipment [Line Items]
Total property and equipment	$ 24,324	$ 17,342
Accumulated depreciation and amortization	(11,517)	(7,814)
Property and equipment, net	12,807	9,528
Computer and Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	10,982	8,787
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment	7,134	4,201
Website and Internal-Use Software
Property Plant And Equipment [Line Items]
Total property and equipment	4,384	2,902
Office Equipment and Furniture
Property Plant And Equipment [Line Items]
Total property and equipment	$ 1,824	$ 1,452

Consolidated Balance Sheet Co35

Consolidated Balance Sheet Components - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Depreciation and amortization	$ 1,303	$ 1,351	$ 3,883	$ 4,201

Consolidated Balance Sheet Co36

Consolidated Balance Sheet Components - Schedule of Accrued Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Accrued royalty expense	$ 14,549	$ 14,940
Accrued inventory	11,325	4,274
Accrued payroll and related expenses	4,352	5,342
Accrued cost of revenue	9,004	7,264
Accrued payments to content publishers	17,651	8,554
Other accrued expenses	8,617	5,782
Total accrued liabilities	$ 65,498	$ 46,156

Consolidated Balance Sheet Co37

Consolidated Balance Sheet Components - Schedule of Deferred Revenue (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Deferred Revenue Arrangement [Line Items]
Deferred revenue, current portion	$ 30,822	$ 23,952
Noncurrent deferred revenue	38,802	29,084
Total deferred revenue	69,624	53,036
Player
Deferred Revenue Arrangement [Line Items]
Deferred revenue, current portion	14,359	13,611
Noncurrent deferred revenue	4,767	5,215
Platform
Deferred Revenue Arrangement [Line Items]
Deferred revenue, current portion	16,463	10,341
Noncurrent deferred revenue	$ 34,035	$ 23,869

Debt - Schedule of Debt Obligat

Debt - Schedule of Debt Obligations (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Total debt obligations	$ 25,000	$ 15,000
Compounding interest due at maturity	255
Less unamortized debt discount and issuance costs	(2,212)
Balance	23,043	15,000
Current portion of long-term debt		(15,000)
Long-term debt, less current portion	23,043
Term Loan
Debt Instrument [Line Items]
Total debt obligations	$ 25,000
Line of Credit
Debt Instrument [Line Items]
Total debt obligations		$ 15,000

Debt - Additional Information (

Debt - Additional Information (Details) - USD ($)	1 Months Ended			9 Months Ended	12 Months Ended
	Oct. 31, 2017	Jun. 30, 2017	May 31, 2015	Sep. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Letters of credit outstanding				$ 1,472,000	$ 868,000
Duration of remaining amount available		24 months
Series H Convertible Preferred Stock Warrants
Debt Instrument [Line Items]
Warrants outstanding				408,648
Warrants, exercise price				$ 9.17340
Warrants, exercisable period				10 years
Second Amendment To Restated 2014 Loan and Security Agreement
Debt Instrument [Line Items]
Letters of credit outstanding				$ 1,472,000
Minimum current ratio required under financial covenant		1.25%
Second Amendment To Restated 2014 Loan and Security Agreement | Prime Rate
Debt Instrument [Line Items]
Basis spread on variable rate		1.00%
Second Amendment To Restated 2014 Loan and Security Agreement | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate		2.75%
2017 Subordinated Loan Agreement
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 40,000,000
Subordinated loan agreement minimum borrowing capacity		$ 25,000,000
Facility fee, percentage		1.00%
Payment in kind interest fees, percent		2.50%
2017 Subordinated Loan Agreement | Class B Common Stock | Subsequent Event
Debt Instrument [Line Items]
Cancellation of warrants to purchase common stock	114,933
2017 Subordinated Loan Agreement | Series H Convertible Preferred Stock Warrants
Debt Instrument [Line Items]
Warrants outstanding		408,648
Warrants, exercise price		$ 9.17340
Warrants, exercisable period		10 years
2017 Subordinated Loan Agreement | Minimum
Debt Instrument [Line Items]
Remaining amount to be drawn as installment		$ 5,000,000
Line of credit facility final payment fees, percent		1.00%
2017 Subordinated Loan Agreement | Maximum
Debt Instrument [Line Items]
Line of credit facility final payment fees, percent		4.00%
2017 Subordinated Loan Agreement | Prime Rate
Debt Instrument [Line Items]
Basis spread on variable rate		3.50%
2017 Subordinated Loan Agreement | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate		6.50%
LIBOR Floor rate		1.00%
Silicon Valley Bank | First Amendment To 2014 Restated Loan and Security Agreement
Debt Instrument [Line Items]
Maximum borrowing capacity			$ 5,000,000
Financial covenant terms				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 and requires the Company to maintain a current ratio (calculated as current assets, divided by current liabilities less deferred revenue), greater than or equal to 1.1.
Interest rate on line of credit					3.75%
Line of credit outstanding					$ 15,000,000
Letters of credit outstanding					$ 868,000
Current ratio					110.00%
Silicon Valley Bank | First Amendment To 2014 Restated Loan and Security Agreement | Prime Rate
Debt Instrument [Line Items]
Basis spread on variable rate			2.50%
Revolving Credit Facility | Second Amendment To Restated 2014 Loan and Security Agreement
Debt Instrument [Line Items]
Line of credit outstanding				$ 0
Revolving Credit Facility | Silicon Valley Bank | First Amendment To 2014 Restated Loan and Security Agreement
Debt Instrument [Line Items]
Maximum borrowing capacity			$ 30,000,000

Stockholder's Deficit - Schedul

Stockholder's Deficit - Schedule of Convertible Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Class Of Stock [Line Items]
Shares authorized	84,368,163	84,368,163
Shares outstanding	80,844,138	80,844,138
Liquidation preference	$ 213,109	$ 213,109
Series A Convertible Preferred Stock
Class Of Stock [Line Items]
Price	$ 0.36312	$ 0.36312
Shares authorized	23,020,000	23,020,000
Shares outstanding	23,019,997	23,019,997
Liquidation preference	$ 8,359	$ 8,359
Series B Convertible Preferred Stock
Class Of Stock [Line Items]
Price	$ 0.93808	$ 0.93808
Shares authorized	6,396,071	6,396,071
Shares outstanding	6,396,068	6,396,068
Liquidation preference	$ 6,000	$ 6,000
Series C-1 Convertible Preferred Stock
Class Of Stock [Line Items]
Price	$ 0.54109	$ 0.54109
Shares authorized	9,240,560	9,240,560
Shares outstanding	9,240,558	9,240,558
Liquidation preference	$ 5,000	$ 5,000
Series C-2 Convertible Preferred Stock
Class Of Stock [Line Items]
Price	$ 0.64931	$ 0.64931
Shares authorized	8,950,467	8,950,467
Shares outstanding	7,700,466	7,700,466
Liquidation preference	$ 5,000	$ 5,000
Series D Convertible Preferred Stock
Class Of Stock [Line Items]
Price	$ 2.37840	$ 2.37840
Shares authorized	4,685,755	4,685,755
Shares outstanding	4,204,505	4,204,505
Liquidation preference	$ 10,000	$ 10,000
Series E Convertible Preferred Stock
Class Of Stock [Line Items]
Price	$ 4.35679	$ 4.35679
Shares authorized	11,160,733	11,160,733
Shares outstanding	11,074,655	11,074,655
Liquidation preference	$ 48,250	$ 48,250
Series F Convertible Preferred Stock
Class Of Stock [Line Items]
Price	$ 5.43396	$ 5.43396
Shares authorized	11,041,671	11,041,671
Shares outstanding	11,041,667	11,041,667
Liquidation preference	$ 60,000	$ 60,000
Series G Convertible Preferred Stock
Class Of Stock [Line Items]
Price	$ 7.79730	$ 7.79730
Shares authorized	3,206,239	3,206,239
Shares outstanding	3,206,234	3,206,234
Liquidation preference	$ 25,000	$ 25,000
Series H Convertible Preferred Stock
Class Of Stock [Line Items]
Price	$ 9.17340	$ 9.17340
Shares authorized	6,666,667	6,666,667
Shares outstanding	4,959,988	4,959,988
Liquidation preference	$ 45,500	$ 45,500

Stockholder's Deficit - Convert

Stockholder's Deficit - Convertible Preferred Stock - Additional Information (Details) - Subsequent Event - Initial Public Offering - Class B Common Stock	Oct. 02, 2017shares
Class Of Stock [Line Items]
Convertible preferred stock, Shares converted	80,844,138
Stock conversion ratio	100.00%

Stockholder's Deficit - Common

Stockholder's Deficit - Common Stock - Additional Information (Details) - $ / shares	Sep. 30, 2017	Dec. 31, 2016
Class Of Stock [Line Items]
Common stock, Shares authorized		122,000,000
Common stock, Par value		$ 0.0001
Common stock, Shares issued		4,818,812
Common stock, Shares outstanding		4,818,812
Class A Common Stock
Class Of Stock [Line Items]
Common stock, Shares authorized	1,000,000,000
Common stock, Par value	$ 0.0001
Common stock, Shares issued	0
Common stock, Shares outstanding	0
Class B Common Stock
Class Of Stock [Line Items]
Common stock, Shares authorized	150,000,000
Common stock, Par value	$ 0.0001
Common stock, Shares issued	5,637,785
Common stock, Shares outstanding	5,637,785

Stockholder's Deficit - Sched43

Stockholder's Deficit - Schedule of Reserved Shares of Common Stock for Issuance (Details) - shares	Sep. 30, 2017	Dec. 31, 2016
Class Of Stock [Line Items]
Common stock options issued under stock option plan	27,326,277	22,334,508
Total	111,618,205	105,780,546
Employee Stock Option
Class Of Stock [Line Items]
Common stock reserved for issuance	1,221,824	409,582
Series A Convertible Preferred Stock
Class Of Stock [Line Items]
Conversion of convertible preferred stock	23,019,997	23,019,997
Series B Convertible Preferred Stock
Class Of Stock [Line Items]
Conversion of convertible preferred stock	6,396,068	6,396,068
Series C-1 Convertible Preferred Stock
Class Of Stock [Line Items]
Conversion of convertible preferred stock	9,240,558	9,240,558
Series C-2 Convertible Preferred Stock
Class Of Stock [Line Items]
Conversion of convertible preferred stock	7,700,466	7,700,466
Series C-2 Convertible Preferred Stock Warrants
Class Of Stock [Line Items]
Conversion of convertible preferred stock	1,250,000	1,250,000
Series D Convertible Preferred Stock
Class Of Stock [Line Items]
Conversion of convertible preferred stock	4,204,505	4,204,505
Series D Convertible Preferred Stock Warrants
Class Of Stock [Line Items]
Conversion of convertible preferred stock	481,246	481,246
Series E Convertible Preferred Stock
Class Of Stock [Line Items]
Conversion of convertible preferred stock	11,074,655	11,074,655
Series E Convertible Preferred Stock Warrants
Class Of Stock [Line Items]
Conversion of convertible preferred stock	86,072	86,072
Series F Convertible Preferred Stock
Class Of Stock [Line Items]
Conversion of convertible preferred stock	11,041,667	11,041,667
Series G Convertible Preferred Stock
Class Of Stock [Line Items]
Conversion of convertible preferred stock	3,206,234	3,206,234
Series H Convertible Preferred Stock
Class Of Stock [Line Items]
Conversion of convertible preferred stock	4,959,988	4,959,988
Series H Convertible Preferred Stock Warrants
Class Of Stock [Line Items]
Conversion of convertible preferred stock	408,648
Common Stock Warrants
Class Of Stock [Line Items]
Common stock reserved for issuance		375,000

Stockholder's Deficit - Stock O

Stockholder's Deficit - Stock Option Plan - Additional Information (Details) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
2008 Plan
Class Of Stock [Line Items]
Common stock options available for grant under stock option plan	28,548,101	22,744,090
Percentage Of Voting Rights	10.00%
Stock option vesting period	4 years
Stock option 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%
Equity Incentive Plan
Class Of Stock [Line Items]
Shares vested and exercisable, Aggregate intrinsic value	$ 354,849,000

Stockholder's Deficit - Sched45

Stockholder's Deficit - Schedule of Activity Under Equity Incentive Plan (Details) - 2008 Plan - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Balance, Shares available for grant	409,582
Increase authorization, Shares available for grant	6,250,000
Granted, Shares available for grant	(6,013,312)
Forfeited and expired, Shares available for grant	575,554
Balance, Shares available for grant	1,221,824	409,582
Balance, Number of shares	22,334,508
Granted, Number of shares	6,013,312
Exercised, Number of shares	(445,995)
Forfeited and expired, Number of shares	(575,554)
Balance, Number of shares	27,326,271	22,334,508
Balance, Weighted average exercise price	$ 3.66
Granted, Weighted average exercise price	7.47
Exercised, Weighted average exercise price	3.91
Forfeited and expired, Weighted average exercise price	5.49
Balance, Weighted average exercise price	$ 4.46	$ 3.66
Balance, Weighted average remaining contractual life	6 years 8 months 12 days	6 years 7 months 6 days
Granted, Weighted average grant date fair value per share	$ 3.48

Stockholder's Deficit - Stock B

Stockholder's Deficit - Stock Based Compensation - Additional Information (Details) - USD ($)	9 Months Ended
	Sep. 30, 2017	Oct. 01, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Expected dividends	$ 0
Total intrinsic value of options exercised	1,510,000	$ 350,000
Unrecognized stock compensation expense	$ 33,750,000
Expected weighted average period to recognize unrecognized stock compensation expense	2 years 9 months 19 days

Stockholder's Deficit - Summary

Stockholder's Deficit - Summary of Assumptions Used to Value Stock-Based Awards Granted (Details) - $ / shares	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Oct. 01, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair value of common stock	$ 8.82		$ 6.60
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	5 years 3 months 19 days	5 years 3 months 19 days	5 years 3 months 19 days
Risk-free interest rate	1.84%	1.84%	1.32%
Expected volatility	39.00%	39.00%	44.00%
Fair value of common stock		$ 5.70
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 years 6 months	6 years 6 months	6 years 6 months
Risk-free interest rate	2.03%	2.25%	1.50%
Expected volatility	43.00%	44.00%	46.00%
Fair value of common stock		$ 8.82

Stockholder's Deficit - Summa48

Stockholder's Deficit - Summary of Recognized Employee Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 2,924	$ 2,011	$ 7,517	$ 6,016
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	1,197	651	3,078	1,924
Sales and Marketing
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	808	580	2,099	1,737
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	876	687	2,183	2,102
Player | Cost of Revenue
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	25	30	99	88
Platform | Cost of Revenue
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 18	$ 63	$ 58	$ 165

Stockholder's Deficit - Commo49

Stockholder's Deficit - Common Stock Warrants - Additional Information (Details) - Common Stock Warrants - shares	1 Months Ended
	Jul. 31, 2017	Sep. 30, 2017
Class Of Warrant Or Right [Line Items]
Conversion of common stock warrants	357,283
Number of common stock warrants expired	375,000
Warrants outstanding		0

Stockholder's Deficit - Sched50

Stockholder's Deficit - Schedule of Convertible Preferred Stock Warrants (Details) - $ / shares	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Series C-2 Preferred Stock Warrants
Class Of Warrant Or Right [Line Items]
Number Outstanding September 30, 2017	1,250,000	1,250,000
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 September 30, 2017	249,999	249,999
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 September 30, 2017	168,180	168,180
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 September 30, 2017	63,067	63,067
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 September 30, 2017	86,072	86,072
Issuance Date	Apr. 27, 2012
Warrants, exercise price	$ 3.48546
Warrants, exercisable period	10 years
Series H Preferred Stock Warrants
Class Of Warrant Or Right [Line Items]
Number Outstanding September 30, 2017	408,648
Issuance Date	Jun. 9, 2017
Warrants, exercise price	$ 9.17340
Warrants, exercisable period	10 years
Preferred Stock Warrants
Class Of Warrant Or Right [Line Items]
Number Outstanding September 30, 2017	2,225,966	1,817,318

Stockholder's Deficit - Summa51

Stockholder's Deficit - Summary of Assumptions Used to Value Preferred Stock Warrants (Details) - Preferred Stock Warrants	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Minimum
Class Of Warrant Or Right [Line Items]
Expected term (in years)	3 years	3 years 2 months 12 days
Risk-free interest rate	1.50%	0.70%
Volatility	43.50%	46.20%
Maximum
Class Of Warrant Or Right [Line Items]
Expected term (in years)	9 years 8 months 12 days	3 years 10 months 25 days
Risk-free interest rate	2.30%	1.60%
Volatility	50.70%	47.80%

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017USD ($)	Oct. 01, 2016USD ($)	Sep. 30, 2017USD ($)Vendor	Oct. 01, 2016USD ($)	Dec. 31, 2016USD ($)
Commitments And Contingencies [Line Items]
Rent expense	$ 1,716,000	$ 1,122,000	$ 4,805,000	$ 3,505,000
Letters of credit outstanding	1,472,000		$ 1,472,000		$ 868,000
Minimum
Commitments And Contingencies [Line Items]
Letters of credit expiration date			Jan. 31, 2018
Maximum
Commitments And Contingencies [Line Items]
Letters of credit expiration date			Aug. 31, 2018
Manufacturing
Commitments And Contingencies [Line Items]
Number of vendors having purchase commitments | Vendor			1
Purchase commitments for inventory	87,151,000		$ 87,151,000
Manufacturing | Accrued Liabilities
Commitments And Contingencies [Line Items]
Loss on purchase obligation for inventory			1,366,000		2,040,000
Content License
Commitments And Contingencies [Line Items]
Purchase obligation that do not yet Meet criteria for asset recognition	1,611,000		1,611,000
Content License | Accrued Liabilities
Commitments And Contingencies [Line Items]
Purchase commitments for inventory	$ 506,000		$ 506,000		$ 0
Player | Minimum
Commitments And Contingencies [Line Items]
Product Warranty Term			12 months
Player | Maximum
Commitments And Contingencies [Line Items]
Product Warranty Term			24 months

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Income Tax Disclosure [Abstract]
Income tax expense (benefit)	$ 58	$ 50	$ 144	$ 103

Related Party Disclosures - Add

Related Party Disclosures - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016	Dec. 31, 2016
Related Party Transaction [Line Items]
Receivable from related parties	$ 153		$ 153		$ 148
Strategic Investors
Related Party Transaction [Line Items]
Revenue from related parties	153	$ 121	243	$ 627
Receivable from related parties	$ 153		$ 153		$ 148

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, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Numerator:
Net loss allocable to common stockholders	$ (46,235)	$ (12,743)	$ (70,450)	$ (45,985)
Denominator:
Weighted-average shares used in computing net loss per share, basic and diluted	5,259,796	4,784,170	4,998,727	4,724,767
Net loss per share, basic and diluted	$ (8.79)	$ (2.66)	$ (14.09)	$ (9.73)

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	9 Months Ended
	Sep. 30, 2017	Oct. 01, 2016
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted net loss per share	110,448,067	103,669,272
Employee Stock Option
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted net loss per share	27,326,277	20,628,248
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	51,686	4,566
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		375,000
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	2,225,966	1,817,320
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	80,844,138	80,844,138

Segment Information - Additiona

Segment Information - Additional Information (Details) - segment	9 Months Ended	12 Months Ended
	Sep. 30, 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 Player Segment Revenue (Details) - Net Revenue - Customer Concentration Risk	3 Months Ended			9 Months Ended
	Sep. 30, 2017		Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Customer A
Entity Wide Revenue Major Customer [Line Items]
Concentration risk	10.00%		16.00%		14.00%
Customer B
Entity Wide Revenue Major Customer [Line Items]
Concentration risk			11.00%		12.00%
Customer C
Entity Wide Revenue Major Customer [Line Items]
Concentration risk	18.00%		25.00%	19.00%	25.00%
Player | Customer A
Entity Wide Revenue Major Customer [Line Items]
Concentration risk	19.00%		22.00%	15.00%	19.00%
Player | Customer B
Entity Wide Revenue Major Customer [Line Items]
Concentration risk		[1]	10.00%	10.00%	11.00%
Player | Customer C
Entity Wide Revenue Major Customer [Line Items]
Concentration risk	32.00%		33.00%	32.00%	33.00%
[1]	Less than 10%

Segment Information - Schedul59

Segment Information - Schedule of Customer Accounting for 10% or More of Platform Segment Revenue (Details) - Platform - Net Revenue - Customer Concentration Risk	3 Months Ended			9 Months Ended
	Sep. 30, 2017		Oct. 01, 2016	Sep. 30, 2017		Oct. 01, 2016
Customer 1
Entity Wide Revenue Major Customer [Line Items]
Concentration risk		[1]	14.00%		[1]	17.00%
Customer 3
Entity Wide Revenue Major Customer [Line Items]
Concentration risk	14.00%		12.00%	13.00%			[1]
[1]	Less than 10%

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - USD ($)	Oct. 02, 2017	Oct. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Subsequent Event [Line Items]
Common stock, Shares authorized				122,000,000
Common stock, Par value				$ 0.0001
Subsequent Event | Class B Common Stock Warrants
Subsequent Event [Line Items]
Number of common stock warrants expired		1,043,009
Subsequent Event | 2017 Subordinated Loan Agreement
Subsequent Event [Line Items]
Loss on extinguishment of debt		$ 2,338,000
Class A Common Stock
Subsequent Event [Line Items]
Common stock, Shares authorized			1,000,000,000
Common stock, Par value			$ 0.0001
Class B Common Stock
Subsequent Event [Line Items]
Common stock, Shares authorized			150,000,000
Common stock, Par value			$ 0.0001
Class B Common Stock | Subsequent Event
Subsequent Event [Line Items]
Number of shares issued upon exercise of warrants		956,511
Class B Common Stock | Subsequent Event | 2017 Subordinated Loan Agreement
Subsequent Event [Line Items]
Cancellation of warrants to purchase common stock		114,933
Initial Public Offering | Subsequent Event
Subsequent Event [Line Items]
Preferred stock, Shares authorized	10,000,000
Preferred stock, Par value	$ 0.0001
Initial Public Offering | Class A Common Stock | Subsequent Event
Subsequent Event [Line Items]
Number of shares sold	10,350,000
Share sold price per share	$ 14
Net proceeds from shares sold	$ 134,757,000
Underwriting discounts and commissions	10,143,000
Offering costs incurred	$ 4,000,000
Common stock, Shares authorized	1,000,000,000
Common stock, Par value	$ 0.0001
Initial Public Offering | Class B Common Stock | Subsequent Event
Subsequent Event [Line Items]
Convertible preferred stock, Shares converted	80,844,138
Stock conversion ratio	100.00%
Common stock, Shares authorized	150,000,000
Common stock, Par value	$ 0.0001
Over-Allotment Option | Class A Common Stock | Subsequent Event
Subsequent Event [Line Items]
Number of shares sold	1,350,000