Roku (ROKU) 10-K 26 Feb 21 2020 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Jan. 31, 2021	Jun. 30, 2020
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Trading Symbol	ROKU
Entity Registrant Name	ROKU, INC
Entity Central Index Key	0001428439
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity File Number	001-38211
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	26-2087865
Entity Address, Address Line One	1155 Coleman Avenue
Entity Address, City or Town	San Jose
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	95110
City Area Code	408
Local Phone Number	556-9040
Document Annual Report	true
Document Transition Report	false
Entity Interactive Data Current	Yes
Title of 12(b) Security	Class A Common Stock, $0.0001 par value
Security Exchange Name	NASDAQ
Entity Public Float			$ 12,291,076,562
ICFR Auditor Attestation Flag	true
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE Part III incorporates by reference certain information from the Registrant’s definitive proxy statement (the “2020 Proxy Statement”) for the 2021 Annual Meeting of Stockholders. The 2020 Proxy Statement will be filed with the Securities and Exchange Commission within 120 days of the registrant’s fiscal year ended December 31, 2020.
Class A Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		111,081,169
Class B Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		17,340,776

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current Assets:
Cash and cash equivalents	$ 1,092,815	$ 515,479
Restricted cash	434	1,854
Accounts receivable, net of allowances of $41,236 and $27,521 as of	523,852	332,673
Inventories	53,895	49,714
Prepaid expenses and other current assets	26,644	25,943
Total current assets	1,697,640	925,663
Property and equipment, net	155,197	103,262
Operating lease right-of-use assets	266,197	283,291
Intangible assets, net	62,181	76,668
Goodwill	73,058	74,116
Other non-current assets	16,269	7,234
Total Assets	2,270,542	1,470,234
Current Liabilities:
Accounts payable	112,314	115,227
Accrued liabilities	347,668	198,347
Current portion of long-term debt	4,874	4,866
Deferred revenue, current portion	55,465	39,861
Total current liabilities	520,321	358,301
Long-term debt, non-current portion	89,868	94,742
Deferred revenue, non-current portion	21,283	15,370
Operating lease liability, non-current portion	307,936	301,694
Other long-term liabilities	3,119	1,701
Total Liabilities	942,527	771,808
Commitments and contingencies (Note 12)
Stockholders’ Equity:
Common stock, $0.0001 par value; 1,150,000 (Class A - 1,000,000 and Class B - 150,000) shares authorized as of December 31, 2020 and 2019; 128,004 (Class A - 110,645 and Class B - 17,359) shares and 119,897 (Class A - 93,574 and Class B - 26,323) shares issued and outstanding as of December 31, 2020 and 2019, respectively	13	12
Additional paid-in capital	1,660,379	1,012,218
Accumulated other comprehensive income	29	29
Accumulated deficit	(332,406)	(313,833)
Total stockholders’ equity	1,328,015	698,426
Total Liabilities and Stockholders’ Equity	$ 2,270,542	$ 1,470,234

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accounts receivable, allowances	$ 41,236	$ 27,521
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	1,150,000,000	1,150,000,000
Common stock, shares issued	128,004,000	119,897,000
Common stock, shares outstanding	128,004,000	119,897,000
Class A Common Stock
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	110,645,000	93,574,000
Common stock, shares outstanding	110,645,000	93,574,000
Class B Common Stock
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	17,359,000	26,323,000
Common stock, shares outstanding	17,359,000	26,323,000

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net Revenue:
Total net revenue	$ 1,778,388	$ 1,128,921	$ 742,506
Cost of Revenue:
Total cost of revenue	970,169	633,697	410,358
Gross Profit:
Total gross profit	808,219	495,224	332,148
Operating Expenses:
Research and development	355,784	265,011	170,692
Sales and marketing	299,457	178,855	102,780
General and administrative	173,231	116,417	71,972
Total operating expenses	828,472	560,283	345,444
Loss from Operations	(20,253)	(65,059)	(13,296)
Other Income (Expense), Net:
Interest expense	(3,432)	(2,366)	(346)
Other income (expense), net	5,233	6,506	4,309
Total other income (expense), net	1,801	4,140	3,963
Loss Before Income Taxes	(18,452)	(60,919)	(9,333)
Income tax (benefit) expense	(945)	(982)	(476)
Net Loss Attributable to Common Stockholders	$ (17,507)	$ (59,937)	$ (8,857)
Net loss per share attributable to common stockholders—basic and diluted	$ (0.14)	$ (0.52)	$ (0.08)
Weighted-average shares used in computing net loss per share attributable to common stockholders—basic and diluted	123,978	115,218	104,618
Platform | Services
Net Revenue:
Total net revenue	$ 1,267,744	$ 740,776	$ 416,863
Cost of Revenue:
Total cost of revenue	503,177	262,655	120,543
Gross Profit:
Total gross profit	764,567	478,121	296,320
Player | Goods
Net Revenue:
Total net revenue	510,644	388,145	325,643
Cost of Revenue:
Total cost of revenue	466,992	371,042	289,815
Gross Profit:
Total gross profit	$ 43,652	$ 17,103	$ 35,828

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net Loss Attributable to Common Stockholders	$ (17,507)	$ (59,937)	$ (8,857)
Other comprehensive gain (loss), net of tax:
Unrealized gain (loss) on short-term investments, net of tax		17	(17)
Foreign currency translation adjustment		29
Other comprehensive gain (loss), net of tax		46	(17)
Comprehensive Net Loss	$ (17,507)	$ (59,891)	$ (8,874)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Accumulated DeficitCumulative Effect, Period of Adoption, Adjustment
Balance at Dec. 31, 2017	$ 152,279		$ 10	$ 435,607		$ (283,338)
Balance (Accounting Standards Update 2016-16) at Dec. 31, 2017		$ (40)					$ (40)
Balance (Accounting Standards Update 2014-09) at Dec. 31, 2017		38,339					38,339
Balance, Shares at Dec. 31, 2017			99,157
Vesting of early exercised stock options	239			239
Issuance of common stock pursuant to equity incentive plans, net of taxes	25,034		$ 1	25,033
Issuance of common stock pursuant to equity incentive plans, net of taxes, Shares			10,481
Issuance of common stock pursuant to exercise of common stock warrants, net, Shares			141
Stock-based compensation expense	37,674			37,674
Share repurchases, Shares			(9)
Unrealized gain (loss) on short-term investments	(17)				$ (17)
Net loss	(8,857)					(8,857)
Balance at Dec. 31, 2018	244,651		$ 11	498,553	(17)	(253,896)
Balance, Shares at Dec. 31, 2018			109,770
Vesting of early exercised stock options	86			86
Issuance of common stock pursuant to equity incentive plans, net of taxes	28,182		$ 1	28,181
Issuance of common stock pursuant to equity incentive plans, net of taxes, Shares			6,169
Issuance of common stock pursuant in connection with at-the-market offerings, net of issuance costs	330,539			330,539
Issuance of common stock pursuant in connection with at-the-market offerings, net of issuance costs, Shares			3,389
Issuance of common stock in connection with acquisition	69,684			69,684
Issuance of common stock in connection with acquisition, Shares			571
Stock-based compensation expense	85,175			85,175
Share repurchases, Shares			(2)
Unrealized gain (loss) on short-term investments	17				17
Foreign currency translation adjustment	29				29
Net loss	(59,937)					(59,937)
Balance at Dec. 31, 2019	698,426		$ 12	1,012,218	29	(313,833)
Balance (Accounting Standards Update 2016-13) at Dec. 31, 2019		$ (1,066)					$ (1,066)
Balance, Shares at Dec. 31, 2019			119,897
Vesting of early exercised stock options	38			38
Issuance of common stock pursuant to equity incentive plans, net of taxes	16,806		$ 1	16,805
Issuance of common stock pursuant to equity incentive plans, net of taxes, Shares			4,107
Issuance of common stock pursuant in connection with at-the-market offerings, net of issuance costs	497,242			497,242
Issuance of common stock pursuant in connection with at-the-market offerings, net of issuance costs, Shares			4,000
Stock-based compensation expense	134,076			134,076
Net loss	(17,507)					(17,507)
Balance at Dec. 31, 2020	$ 1,328,015		$ 13	$ 1,660,379	$ 29	$ (332,406)
Balance, Shares at Dec. 31, 2020			128,004

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Statement Of Stockholders Equity [Abstract]
At the market offerings issuance cost	$ 6.8	$ 6.4

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net loss	$ (17,507)	$ (59,937)	$ (8,857)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	36,206	15,669	8,389
Stock-based compensation expense	134,076	85,175	37,674
Amortization of right-of-use assets	28,743	22,328
Amortization of content assets	22,392	2,914
Provision for doubtful accounts	3,801	704	876
Other items net	524	1,101	1,465
Changes in operating assets and liabilities:
Accounts receivable	(196,046)	(110,225)	(50,673)
Inventories	(4,181)	(14,129)	(2,953)
Prepaid expenses and other current assets	(3,450)	(9,934)	(306)
Deferred cost of revenue		1,143	2,261
Other noncurrent assets	(1,128)	(3,060)	(732)
Accounts payable	6,410	9,409	(98)
Accrued liabilities	103,218	74,512	17,914
Operating lease liabilities	12,999	11,658
Other long-term liabilities	618	(3,024)	(1,101)
Deferred revenue	21,517	(10,597)	10,063
Net cash provided by operating activities	148,192	13,707	13,922
Cash flows from investing activities:
Purchase of property and equipment	(82,382)	(77,180)	(18,327)
Purchase of business, net of cash acquired		(68,132)
Proceeds from escrows associated with acquisition	1,058
Purchase of intangible assets		(7,428)
Purchases of short-term investments		(12,365)	(53,806)
Sales/maturities of short-term investments		54,810	12,000
Net cash used in investing activities	(81,324)	(110,295)	(60,133)
Cash flows from financing activities:
Proceeds from borrowings, net of issuance costs	69,325	99,608
Repayments of borrowings	(74,325)
Holdback payment for a prior business acquisition			(500)
Proceeds from equity issued under incentive plans, net of repurchases	16,806	28,181	25,025
Proceeds from equity issued under at-the-market offerings, net of offering costs	497,242	330,539
Net cash provided by financing activities	509,048	458,328	24,525
Net increase (decrease) in cash, cash equivalents and restricted cash	575,916	361,740	(21,686)
Effect of exchange rate changes on cash, cash equivalents and restricted cash		29
Cash, cash equivalents and restricted cash —Beginning of period	517,333	155,564	177,250
Cash, cash equivalents and restricted cash —End of period	1,093,249	517,333	155,564
Cash, cash equivalents and restricted cash at end of period:
Cash and cash equivalents	1,092,815	515,479	155,564
Restricted cash	434	1,854
Cash, cash equivalents and restricted cash —End of period	1,093,249	517,333	155,564
Supplemental disclosures of cash flow information:
Cash paid for interest	3,470	3,095	493
Cash paid for income taxes	1,014	759	564
Supplemental disclosures of noncash investing and financing activities:
Issuance of common stock for business combinations		69,684
Unpaid portion of property and equipment purchases	$ 1,242	10,762	$ 1,617
Unpaid portion of acquisition related expenses		2,190
Unpaid portion of purchased intangibles		400
Unpaid portion of at-the-market offering costs		$ 144

The Company

The Company	12 Months Ended
	Dec. 31, 2020
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 platform revenue from advertising, content distribution, audience development, billing services and licensing activities and player revenue from the sale of streaming players and audio products.

Significant Accounting Policies

Significant Accounting Policies and Basis of Presentation	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Significant Accounting Policies and Basis of Presentation	2. SIGNIFICANT ACCOUNTING POLICIES AND BASIS OF PRESENTATION Basis of Presentation and Principles of Consolidation The consolidated financial statements, which include the accounts of Roku, Inc. and its wholly-owned subsidiaries, have been prepared in conformity with accounting principles generally accepted in the United States (“U.S. GAAP”). All intercompany accounts and transactions have been eliminated in consolidation. Reclassification of Prior Year Presentation Certain prior period amounts within cash flow from operations in the statement of cash flows, have been reclassified to conform to current period presentation. These reclassifications had no effect on net cash provided by operating activities for any period reported. Use of Estimates The preparation of the Company’s consolidated financial statements in accordance with U.S. GAAP requires management to make certain estimates, judgements, and assumptions that affect the reported amounts of assets, liabilities, net revenue and expenses. Significant items subject to such estimates and assumptions include: for revenue recognition, determining the nature and timing of satisfaction of performance obligations, variable consideration, determining the stand-alone selling prices of performance obligations, gross versus net revenue recognition, evaluation of customer versus vendor relationships, and other obligations such as sales return reserves and sales incentive programs; the impairment of goodwill and intangible assets; useful lives of tangible and intangible assets; allowances for doubtful accounts; the valuation of deferred income tax assets; and stock-based compensation. 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 and assumptions. Comprehensive Loss The comprehensive loss is equal to the net loss for the year ended December 31, 2020. Comprehensive loss includes unrealized gains on the Company’s short-term investments and foreign currency translation adjustments for the year ended December 31, 2019. Comprehensive loss includes unrealized losses on the Company’s short-term investments for the year ended December 31, 2018. Income taxes on the unrealized gains or losses are not material. Foreign Currency The functional currency of the Company’s foreign subsidiaries is the U.S. dollar. Monetary assets and liabilities of these subsidiaries are remeasured into U.S. dollars from the local currency at rates in effect at period-end and nonmonetary assets and liabilities are remeasured at historical rates. Revenues and expenses are remeasured at average exchange rates in effect during each period. Foreign currency gains or losses from re-measurement and transaction gains or losses are recorded as other income (expense), net in the consolidated statements of operations. During the year ended December 31, 2020, the Company recorded a foreign currency gain of $1.3 million. During the years ended December 31, 2019 and 2018, the Company recorded a foreign currency loss of $0.2 million and $0.5 million, respectively. Cash and Cash Equivalents The Company considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. As of December 31, 2020, two financial institutions managed 46% and 26%, respectively, of the Company’s total cash and cash equivalents balance. As of December 31, 2019, the same two financial institutions managed 65% and 34%, respectively, of the Company’s total cash and cash equivalents balance. Accounts Receivable, net Accounts receivable are typically unsecured and are derived from revenue earned from customers. They are stated at invoice value less estimated allowances for sales returns, sales incentives and doubtful accounts. The Company performs ongoing credit evaluations of its customers and maintains allowances for potential credit losses and doubtful accounts. The Company considers historical experience, ongoing promotional activities, historical claim rate and other factors to determine the allowances for sales returns and sales incentives. Allowance for Sales Returns : Allowance for sales returns consist of the following activities (in thousands): Years Ended December 31, 2020 2019 2018 Beginning balance $ (6,550 ) $ (7,335 ) $ (6,907 ) Charged to revenue (14,594 ) (15,541 ) (17,396 ) Utilization of sales return reserve 15,232 16,326 16,968 Ending balance $ (5,912 ) $ (6,550 ) $ (7,335 ) Allowance for Sales Incentives : Allowance for sales incentives consisted of the following activities (in thousands): Years Ended December 31, 2020 2019 2018 Beginning balance $ (19,476 ) $ (13,750 ) $ (10,442 ) Charged to revenue (68,315 ) (65,676 ) (50,958 ) Utilization of sales incentive reserve 56,953 59,950 47,650 Ending balance $ (30,838 ) $ (19,476 ) $ (13,750 ) Allowance for Doubtful Accounts : Allowance for doubtful accounts consisted of the following activities (in thousands): Years Ended December 31, 2020 2019 2018 Balance, beginning of period $ (1,140 ) (686 ) (63 ) Impact of adoption of ASU 2016-13 (1,066 ) — — Adjusted balance, beginning of period (2,206 ) (686 ) (63 ) Provision for doubtful accounts $ (3,801 ) $ (704 ) $ (876 ) Adjustments for recovery and write-off 1,826 250 253 Balance, end of period (4,181 ) (1,140 ) (686 ) Customer H accounted for 11% of the accounts receivable, net balance as of December 31, 2020. The Company did not have any customer that accounted for more than 10% of its accounts receivable, net balance as of December 31, 2019. Business Combinations The Company determines whether a transaction meets the definition of a business combination before applying the acquisition method of accounting to that transaction. The Company allocates the fair value of the purchase consideration of its acquisitions to the tangible and intangible assets acquired and liabilities assumed, based on their estimated fair values. The excess of the fair value of purchase consideration over the fair values of identifiable assets and liabilities is recorded as goodwill. The operating results of acquired business is included in the Company’s consolidated statement of operations beginning on their effective acquisition date. Acquisition-related expenses and certain acquisition restructuring and other related charges are recognized separately from the business combination and are expensed as incurred. Contingent consideration arrangements are recognized at fair value as of the acquisition date with subsequent fair value adjustments recorded in operations. While the Company uses its best estimates and assumptions to accurately value assets acquired and liabilities assumed at the acquisition date, estimates are inherently uncertain and subject to refinement. As a result, during the measurement period, which may be up to one year from the acquisition date, the Company may record adjustments to the assets acquired and liabilities assumed with the corresponding offset to goodwill. In addition, uncertain tax positions and tax-related valuation allowances are initially recorded in connection with a business combination as of the acquisition date. The Company continues to collect information and reevaluates these estimates and assumptions quarterly and records any adjustments to the Company’s preliminary estimates to goodwill provided that the Company is within the measurement period. Upon the conclusion of the measurement period or final determination of the values of assets acquired or liabilities assumed, whichever comes first, any subsequent adjustments are recorded to our consolidated statements of operations. Intangible Assets Intangible assets acquired through business combinations are recorded at their fair values upon acquisition close. Intangible assets are amortized using the straight-line method over their estimated useful lives. The Company evaluates the estimated remaining useful lives of its intangible assets annually and when events or changes in circumstances warrant a revision to the remaining periods of amortization. Impairment Assessments The Company evaluates goodwill for possible impairment at least annually during the fourth quarter of each fiscal year or more often, if and when circumstances indicate that goodwill may be impaired. This includes but is not limited to significant adverse changes in the business climate, market conditions, or other events that indicate that it is more likely than not that the fair value of a reporting unit is less than its carrying value. In performing its annual assessment, the Company can opt to perform a qualitative assessment to test a reporting unit’s goodwill for impairment or it can directly perform a quantitative assessment. Based on the Company’s qualitative assessment, if it is determined that the fair value of our reporting unit is, more likely than not, less than its carrying amount, then the quantitative assessment is performed. Any excess of the reporting unit's carrying amount over its fair value is be recorded as an impairment loss. The Company reviews long-lived assets, intangible assets and capitalized licensed content assets with finite lives for impairment when events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable or that the useful lives of those assets are no longer appropriate. The Company assesses these assets for impairment based on their estimated undiscounted future cash flows. If the carrying value of the asset group exceeds the estimated future undiscounted cash flows, the Company recognizes an impairment loss based on the excess of the carrying amount over the fair value of the asset group. The Company did not recognize any impairment for goodwill, intangible assets or capitalized licensed content assets in any periods reported. The impairments of operating right-of-use assets during the years ended December 31, 2020 and 2019 were not material. Revenue Recognition Revenue is recognized upon transfer of control of promised goods or services to customers in an amount that reflects the consideration the Company expects to receive in exchange for those goods or services. The Company’s contracts include various product or services or a combination of both, which are generally capable of being distinct and are accounted for as separate performance obligations. The Company’s contracts often contain multiple distinct performance obligations. The Company estimates the transaction price of a contract based on the expected value for which a significant reversal of revenue is not expected to occur. The estimate of the variable consideration is based on the assessment of historical, current, and forecasted performance noted and expected from the performance obligation. In arrangements with multiple performance obligations, the estimated transaction price of each contract is allocated to each distinct performance obligation based on relative stand-alone selling price (“SSP”). For performance obligations routinely sold separately, the SSP is determined by evaluating such stand-alone sales. For those performance obligations that are not routinely sold separately, the Company determines SSP based on market conditions and other observable inputs. When the Company sells third-party goods and services, it evaluates whether the Company is the principal, and reports revenues on a gross basis, or an agent, and reports revenues on a net basis. In this assessment, the Company considers if it obtains control of the specified goods or services before they are transferred to the customer, as well as other indicators such as the party primarily responsible for fulfillment, inventory risk, and discretion in establishing price. Revenue is recorded net of taxes collected from customers which are subsequently remitted to the relevant government authority. The Company does not capitalize any cost associated with contract acquisition because it applies a practical expedient and expenses commissions when incurred as most direct contract acquisition costs relate to contracts that are recognized over a period of one year or less. Sales commissions are included in Sales and marketing expenses in the consolidated statements of operations. As-invoiced practical expedient is applied when the amount of consideration the Company has a right to invoice corresponds directly with the value to the customer of the entity’s performance completed to date. Nature of Products and Services Platform segment: The Company generates platform revenue from the sale of digital advertising and related services, content distribution services, subscription and transaction revenue shares, Premium Subscriptions, billing services, sale of branded channel buttons on remote controls and licensing arrangements with service operators and TV brands. The Company sells digital advertising directly to marketers or through advertising agencies. Revenue from advertising is mostly generated through video and display advertising delivered through advertising impressions. Advertising is typically sold on a cost-per-thousand (“CPM”) basis and is evidenced by an Insertion Order (“IO”). Revenue is recognized as the number of impressions are delivered. IOs may include multiple performance obligations as they contain distinct advertising products or services. For such arrangements, the Company allocates revenue to each distinct performance obligation based on their relative SSP. The Company also generates revenue from customers using its platform. For that it charges a platform fee, which is a percentage of a customer’s advertising inventory spend during the month, along with data and any add-on features purchased through the platform. The Company recognizes revenue on either a gross or net basis for digital advertising based on its determination as to whether it is acting as the principal in the revenue generation process or as an agent. Where the Company is the principal, it controls the advertising inventory before it is transferred to its customers. This is further supported by the Company being primarily responsible to its customers and having a level of discretion in establishing pricing. Advertising arrangements comprised of multiple performance obligations are recognized either at a point in time or over time depending on the nature of the distinct performance obligation. The Company’s content distribution revenue sharing arrangements include cash or non-cash consideration. The revenue sharing arrangements generally apply to new subscriptions for accounts that sign up for new services and at the time of a movie rental or purchase. Revenue is recognized on a net basis as the Company is deemed to be the agent between content publishers and end users. Revenue is recognized on a time elapsed basis, by day, as the services are delivered over the contractual distribution term. Non-cash consideration is usually in the form of advertising inventory, the fair value of which is determined based on relevant internal and third-party data. The Company sells monthly subscriptions for premium content on The Roku Channel for varying fees for different content. Revenue from such premium subscription fees is recognized on a gross basis over the service period as the Company is deemed to be the principal in the relationship with the end user. The Company obtains control of the content before transferring to the end user and has latitude in establishing pricing. The Company pays fixed fees to the providers of premium content on The Roku Channel based on the contractual arrangement and recognizes that in Cost of revenue, platform. The Company sells branded channel buttons on remote controls of streaming devices that provide one-touch access to a publisher’s content. The Company typically receives a fixed fee per button for each unit sold over a defined distribution period. Revenue is recognized on a time elapsed basis, by day, over the distribution term. The Company licenses the Roku OS, including updates and upgrades, to TV brands and service operators. The licensing revenue is recognized at a point in time, when the Company makes the intellectual property available and the control transfers to the customer. The revenue allocated to unspecified upgrades is recognized on a time elapsed basis, by day, over the service period. Professional services revenue is recognized as services are provided or accepted. Hosting fees are recognized on a time elapsed basis, by day, over the service period. Player segment: The Company sells the majority of its players and audio products to retail distribution channels in the U.S., including brick and mortar and online retailers, as well as through the Company’s website. Player revenue primarily consists of hardware, embedded software and unspecified upgrades on a when and if-available basis. The hardware and embedded software are considered as one performance obligation and revenue is recognized at a point in time when the control transfers to the customer. Unspecified upgrades or enhancements are available to customers on a when-and-if available basis. The Company records the allocated value of the unspecified upgrades as deferred revenue and recognizes it as player revenue ratably on a time elapsed basis over the estimated economic life of the associated players. The Company’s player revenue includes allowances for sales returns and sales incentives in the estimated transaction price. These estimates are based on historical experience and anticipated performance. Shipping charges billed to customers are included in Revenue and the related shipping costs are included in Cost of revenue. Leases On January 1, 2019, the Company adopted the guidance in Leases (Topic 842), Operating leases are included in operating lease right-of-use assets, accrued liabilities, and operating lease liability in our consolidated balance sheets. represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent its obligation to make lease payments arising from the lease. Fair Value of Financial Instruments The Company defines fair value as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The Company applies fair value accounting for all assets and liabilities that are recognized or disclosed at fair value in the consolidated financial statements. The carrying amounts reported in the consolidated financial statements for cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities approximate their fair values due to their short-term nature. The carrying amount of debt approximates fair value due to its variable interest rates. Inventories The Company’s inventories consist primarily of finished goods and are stated at the lower of cost or net realizable value with cost determined on a first-in, first-out basis. Provisions are made if the cost of the inventories exceeds their net realizable value. The Company evaluates inventory levels and purchase commitments for excess and obsolete products, based on management’s assessment of future demand and market conditions. Property and Equipment Property and equipment are recorded at cost and depreciated using the straight-line method over their estimated useful lives of the assets, generally ranging between eighteen months and five years The Company capitalizes costs to develop its internal-use software. Costs that relate to the planning and post-implementation phases of development are expensed as incurred. Costs are capitalized when preliminary efforts are successfully completed, management has authorized and committed to funding the project, and it is probable that the project will be completed and will be used as intended. Costs incurred for enhancements that are expected to result in additional material functionality are capitalized. During the years ended December 31, 2020, 2019 and 2018, the Company capitalized internal-use software development costs of $2.2 million, $0.1 million and $1.0 million, respectively. Capitalized costs are amortized using the straight-line method over the estimated useful life of the asset, which is generally two to three years, beginning when the asset is ready for its intended use. During the years ended December 31, 2020, 2019 and 2018, the Company amortized expenses of $0.5 million, $1.6 million and $2.0 million, respectively. Deferred Revenue The Company’s deferred revenue reflects fees received from licensing and service arrangements, including advertising, that will be recognized as revenue over time or as services are rendered. Deferred revenue balances consist of the amount of player sales allocated to unspecified upgrades or enhancements on a when-and-if available basis, licensing and services fees from service operators and TV brands, and payments from advertisers and content publishers. Deferred revenue expected to be realized within one year is classified as current liabilities and the remaining is recorded as noncurrent liabilities. Advertising Costs Advertising costs are expensed when incurred and are included in Sales and marketing expense in the consolidated statements of operations. The Company incurred advertising costs of $7.1 million, $7.3 million and $3.0 million for the years December 31, 2020, 2019 and 2018, respectively. Stock-Based Compensation The Company measures compensation expense for all stock-based awards, including restricted stock units and stock options granted to employees, based on the estimated fair value of the award on the date of grant. For restricted stock units, the grant date fair value is based on the closing market price of the Company’s Class A common stock on the date of grant. The fair value of each stock option is estimated using the Black-Scholes option-pricing model. The Company accounts for forfeitures as they occur. Stock-based compensation is recognized on a straight-line basis over the requisite vesting period. Income Taxes The Company accounts for income taxes using an asset and liability approach. Deferred tax assets and liabilities are determined based on the difference between the consolidated financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to affect taxable income. Valuation allowances are established when necessary to reduce deferred tax assets to the amounts that are more likely than not to be realized. Net Loss per Share Since the Company was in a loss position for all periods presented, basic net loss per share is the same as diluted net loss per share for all periods as the inclusion of all potential common shares outstanding and potentially dilutive securities would have been anti-dilutive. Recently Adopted Accounting Standards In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standard Update (“ASU”) 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments . The guidance amended reporting of credit losses for assets held at amortized cost basis and available-for-sale debt securities to require that credit losses on available-for-sale debt securities be presented as an allowance rather than as a write-down. On January 1, 2020, the Company adopted this guidance using the modified retrospective adoption method and recorded a cumulative-effect adjustment to the beginning balance of accumulated deficit of approximately $1.1 million. The measurement of credit losses for newly recognized financial assets and subsequent changes in the allowance for credit losses are recorded in the statements of operations. This impact mainly relates to credit losses recognized on the Company’s doubtful accounts. As the Company did not have any available-for-sale debt securities as of the adoption date, there was no additional impact to accumulated deficit. In March 2019, the FASB issued ASU 2019-02, Entertainment—Films—Other Assets—Film Costs (Subtopic 926-20) and Entertainment—Broadcasters—Intangibles—Goodwill and Other (Subtopic 920-350): Improvements to Accounting for Costs of Films and License Agreements for Program Materials , in order to align the accounting for production costs of an episodic television series with the accounting for production costs of films by removing the content distinction for capitalization. ASU 2019-02 also requires that an entity reassess estimates of the use of a film in a film group and account for any changes prospectively. In addition, ASU 2019-02 requires that an entity test films and license agreements for program material for impairment at a film group level when the film or license agreements are predominantly monetized with other films and license agreements. On January 1, 2020 , the Company adopted the guidance in ASU 2019-02 . There was no material impact to the Company’s consolidated financial statements. The Company also adopted the following ASUs effective January 1, 2020, none of which had a material impact on the Company’s financial position or results of operations. ASU Description ASU 2018-15 Intangibles—Goodwill and Other—Internal-Use Software (Topic 350), Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract ASU 2018-13 Fair Value Measurements (Topic 820), Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement ASU 2017-04 Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment ASU2019-04 Codification Improvements to Topic 326, Financial Instruments—Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments ASU2020-02 Financial Instruments—Credit Losses (Topic 326) and Leases (Topic 842)—Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 119 and Update to SEC Section on Effective Date Related to Accounting Standards Update No. 2016-02, Leases (Topic 842) ASU2020-03 Codification Improvements to Financial Instruments In March 2020, FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting . This guidance provides optional expedients and exceptions for applying U.S. GAAP to contract modifications, hedging relationships, and other transactions that reference London Interbank Offered Rate (“LIBOR”) that is expected to be discontinued, subject to meeting certain criteria. The guidance is effective as of March 12, 2020 through December 31, 2022. The Company made a policy election in the second quarter of 2020 to elect a different reference rate for the Credit Agreement when LIBOR is discontinued. It is still uncertain when the transition from LIBOR to another reference rate will occur or which reference rate will become the accepted market alternative to LIBOR. Recent Accounting Standards Not Yet Adopted In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes

Revenue

Revenue	12 Months Ended
	Dec. 31, 2020
Revenue From Contract With Customer [Abstract]
Revenue	3. REVENUE The Company’s disaggregated revenues are represented by the two reportable segments discussed in Note 17. The contract balances include the following (in thousands): As of December 31, 2020 2019 2018 Accounts receivable, net $ 523,852 $ 332,673 $ 183,078 Contract assets (included in Prepaid expenses and other current assets) 7,431 3,588 753 Deferred revenue, current portion 55,465 39,861 45,442 Deferred revenue, non-current portion 21,283 15,370 19,594 Total deferred revenue $ 76,748 $ 55,231 $ 65,036 Accounts receivable are recorded at the amount invoiced, net of an allowance for doubtful accounts, sales returns, and sales incentives. Payment terms can vary by customer and contract. The timing of revenue recognition may differ from the timing of invoicing to customers. Contract assets are created when invoicing occurs subsequent to revenue recognition. Contract assets are transferred to accounts receivable when the right to invoice becomes unconditional. The Company’s contract assets are generally current in nature and are included in Prepaid expenses and other current assets. Contract liabilities are included in deferred revenue and reflect consideration invoiced prior to the completion of performance obligations and revenue recognition. Deferred revenue increased by approximately $21.5 million during the year ended December 31, 2020 due to the increase in estimated values of content publisher and licensing partner arrangements and change in the timing of fulfillment of performance obligations of approximately $12.4 million, and higher growth in the player segment, resulting in a net increase in deferred revenue related to unspecified upgrades of approximately $8.4 million. Deferred revenue decreased by approximately $9.8 million during the year ended December 31, 2019 primarily due to revenue recognized of $5.0 million pursuant to customer acceptance of a milestone, and the remaining revenue recognized primarily relates to the Revenue recognized during the year ended December 31, 2020 from amounts included in deferred revenue as of December 31, 2019 was $42.9 million. Revenue recognized during the year ended December 31, 2019 from amounts included in deferred revenue as of December 31, 2018 was $52.5 million. Revenue allocated to remaining performance obligations represents estimated contracted revenue that has not yet been recognized which includes unearned revenue and amounts that will be invoiced and recognized as revenue in future periods. Estimated contracted revenue was $513.7 m illion as of December 31, 2020 of which the Company expects to recognize approximately 55 % over the next 12 months and the remainder thereafter. The Company recognized $14.4 million and $10.9 million during the years ended December 31, 2020 and 2019, respectively, from performance obligations that were satisfied in previous periods due to the changes in transaction price of its revenue contracts. Customer C accounted for 12%, 14% and 18% of the total net revenue during the years ended December 31, 2020, 2019 and 2018, respectively.

Business Combination

Business Combination	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Business Combination	4. business combination On November 8, 2019, the Company acquired all outstanding shares of dataxu, Inc., (“dataxu”) according to the terms and conditions of the Agreement and Plan of Merger, dated as of October 22, 2019 (the “Merger Agreement”) . dataxu is a demand-side platform (“DSP”) that enables marketers to plan and buy video ad campaigns. The acquisition of dataxu’s platform complements the Company’s OTT advertising platform and enables marketers to access a single, data-driven software solution to plan, buy, and optimize their ad spend across TV and OTT providers. The total purchase consideration for dataxu was $147.3 million, which consisted of $77.6 million in cash and $69.7 million for the fair value of the Company’s 571,459 shares of Class A common stock. Pursuant to the Merger Agreement, the Company had deposited $18.8 million into an escrow account to secure certain indemnifications and other potential obligations. As of the year ended December 31, 2020, a balance of $13.6 million is unreleased and remains in the escrow account. The allocation of the purchase consideration to tangible and intangible assets acquired and liabilities assumed on acquisition date is based on estimated fair values and is as follows (in thousands): Assets acquired Fair Values Estimated Useful Lives (in years) Current assets $ 50,829 Restricted cash 1,303 Property and equipment, net 4,503 Intangible assets: Developed Technology 56,400 6.0 Customer relationships 13,400 4.0 Tradename 400 0.5 Goodwill 71,676 Operating lease right-of-use assets 24,658 Other long-term assets 235 Total assets acquired 223,404 Liabilities assumed Current liabilities (51,428 ) Operating lease liabilities (24,658 ) Total liabilities assumed (76,086 ) Total purchase consideration $ 147,318 The fair value estimates of the net assets acquired are based upon calculations and valuations, and those estimates and assumptions regarding certain tangible assets acquired and liabilities assumed. The excess of the total consideration over the tangible assets, identifiable intangible assets, and assumed liabilities is recorded as goodwill. Goodwill is primarily attributable to expected synergies in our advertising offerings and cross-selling opportunities. The goodwill recorded is not deductible for tax purposes. In connection with the acquisition, a deferred tax liability is established for the book/tax differences related to non-goodwill intangible assets. The deferred tax liability is not reflected as the Company also acquired deferred tax assets, including significant net operating losses, that offset the deferred tax liability. Additionally, both companies have full valuation allowances recorded against their respective deferred tax assets, resulting in a net zero adjustment to deferred taxes on the consolidated balance sheets.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2020
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	5. GOODWILL AND INTANGIBLE ASSETS Goodwill Goodwill represents the excess of purchase consideration in a business combination over the fair value of tangible and The following table reflects the carrying value of goodwill (in thousands): Carrying Value Balance as of December 31, 2018 $ 1,382 Addition: dataxu acquisition 72,734 Balance as of December 31, 2019 74,116 Adjustment: dataxu working capital adjustments (1,058 ) Balance as of December 31, 2020 $ 73,058 Goodwill is evaluated for impairment annually. No impairment was recognized during the years ended December 31, 2020, 2019 and 2018. Intangible Assets The following table is the summary of Company’s intangible assets (in thousands): As of December 31, 2020 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted-Average Useful Lives (in years) Developed technology $ 62,367 $ (13,439 ) $ 48,928 5.9 Customer relationships 13,400 (3,908 ) 9,492 4.0 Tradename 400 (400 ) — 0.5 Patents 4,076 (315 ) 3,761 14.0 Intangible assets $ 80,243 $ (18,062 ) $ 62,181 As of December 31, 2019 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted-Average Useful Lives (in years) Developed technology $ 62,367 $ (2,860 ) $ 59,507 5.9 Customer relationships 13,400 (558 ) 12,842 4.0 Tradename 400 (133 ) 267 0.5 Patents 4,076 (24 ) 4,052 14.0 Intangible assets $ 80,243 $ (3,575 ) $ 76,668 The Company recorded expenses of $14.5 million, $2.8 million and $0.6 million for amortization of intangible assets during the years ended December 31, 2020, 2019 and 2018, respectively. In the years ended December 31, 2020 and 2019, the Company recorded amortization of developed technology in Cost of revenue, platform, Cost of revenue, player, Research and development, and General and administrative expenses and recorded amortization of customer relationships and tradename in Sales and marketing expenses in the consolidated statements of operations. In the year ended December 31, 2018, the Company recorded amortization of developed technology in Research and development expenses in the consolidated statements of operations. The estimated future amortization expense for intangible asset for the next five years and thereafter is as follows (in thousands): Year Ending December 31, 2021 $ 14,036 2022 13,666 2023 13,108 2024 10,316 2025 8,750 Thereafter 2,305 Total $ 62,181

Balance Sheet Components

Balance Sheet Components	12 Months Ended
	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	6. Balance sheet components Accounts Receivable, net : Accounts receivable, net consisted of the following (in thousands): As of December 31, 2020 2019 Gross accounts receivable $ 565,088 $ 360,194 Allowance for sales returns (5,912 ) (6,550 ) Allowance for sales incentives (30,838 ) (19,476 ) Allowance for doubtful accounts (4,181 ) (1,140 ) Other allowances (305 ) (355 ) Total allowances (41,236 ) (27,521 ) Total Accounts Receivable, net of allowances $ 523,852 $ 332,673 Property and Equipment, net : Property and equipment, net consisted of the following (in thousands): As of December 31, 2020 2019 Computers and equipment $ 30,859 $ 23,834 Leasehold improvements 144,013 93,239 Website and internal-use software 6,744 6,510 Office equipment and furniture 19,661 12,091 Total property and equipment 201,277 135,674 Accumulated depreciation and amortization (46,080 ) (32,412 ) Property and Equipment, net $ 155,197 $ 103,262 Depreciation and amortization expense, for property and equipment assets, for the years ended December 31, 2020, 2019 and 2018 was $21.7 million, $12.8 million and $7.8 million, respectively. Accrued Liabilities : Accrued liabilities consisted of the following (in thousands): As of December 31, 2020 2019 Payments due to content publishers $ 106,576 $ 57,376 Accrued cost of revenue 98,285 58,149 Marketing, retail and merchandising costs 43,645 7,624 Operating lease liability, current 35,647 17,896 Accrued royalty expense 15,713 18,040 Licensed content liability, current 6,165 1,679 Other accrued expenses 41,637 37,583 Total Accrued Liabilities $ 347,668 $ 198,347 Deferred Revenue : Deferred revenue consisted of the following (in thousands): As of December 31, 2020 2019 Platform, current $ 27,587 $ 18,234 Player, current 27,878 21,627 Total deferred revenue, current 55,465 39,861 Platform, non-current 9,909 6,135 Player, non-current 11,374 9,235 Total deferred revenue, non-current 21,283 15,370 Total Deferred Revenue $ 76,748 $ 55,231

Licensed Content Assets

Licensed Content Assets	12 Months Ended
	Dec. 31, 2020
Capitalized Licensed Content Costs [Abstract]
Licensed Content Assets	7. licensed Content Assets The Company licenses content for streaming on The Roku Channel. The licensing arrangements can be for a fixed fee or variable fee. The licensing arrangements specify the period when the content is available for streaming. The Company capitalizes the fixed content fees and its corresponding liability when the license period begins, the cost of the content is known, and the content is accepted and available for streaming. If the licensing fee is not determinable or reasonably estimable, no asset or liability is recorded, and licensing costs are expenses as incurred. The Company amortizes licensed content assets into Cost of Revenue, Platform, using the straight-line method over the contractual period of availability. The liability is paid in accordance with the contractual terms of the arrangement. On January 1, 2020, the Company adopted the guidance in ASU 2019-02, Entertainment—Films—Other Assets—Film Costs (Subtopic 926-20) and Entertainment—Broadcasters—Intangibles—Goodwill and Other (Subtopic 920-350): Improvements to Accounting for Costs of Films and License Agreements for Program Materials As of December 31, 2020, licensed content assets that met these requirements were $7.9 million and are recorded in “Other non-current assets.” As of December 31, 2019, licensed content assets that met these requirements were $1.7 million and are recorded in Prepaid expenses and other current assets. Payments for content, including additions to content assets and the changes in related liabilities, are classified within Net cash provided by operating activities on the consolidated statements of cash flows. The Company recorded amortization expense of $22.4 million and $2.9 million for the years ended December 31, 2020 and 2019, respectively, in Cost of revenue, platform in the consolidated statements of operations, related to capitalized licensed content assets. The following table reflects the amortization expense for the next three years for capitalized licensed content assets as of December 31, 2020 (in thousands): Year Ending December 31, 2021 $ 6,527 2022 1,338 2023 42 Licensed content assets are primarily monetized together as a unit, referred to as a film group. The film group is evaluated for impairment whenever an event occurs or circumstances change indicating the fair value is less than the carrying value. The Company reviews various qualitative factors and indicators to assess whether the group asset is impaired. As of December 31, 2020, the Company did not recognize any impairment for capitalized licensed content assets.

Fair Value Disclosure

Fair Value Disclosure	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Disclosure	8. FAIR VALUE DISCLOSURE The Company’s financial assets measured at fair value are as follows (in thousands): As of December 31, 2020 As of December 31, 2019 Fair Value Level 1 Fair Value Level 1 Assets: Cash and cash equivalents: Cash $ 1,021,022 $ 1,021,022 $ 463,820 $ 463,820 Money market funds 71,793 71,793 51,659 51,659 Restricted cash 434 434 1,854 1,854 Total assets measured and recorded at fair value $ 1,093,249 $ 1,093,249 $ 517,333 $ 517,333 Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in the principal market (or most advantageous market, in the absence of a principal market) for the asset or liability in an orderly transaction between market participants at the measurement date. Further, the Company maximizes the use of observable inputs and minimizes the use of unobservable inputs in measuring fair value, and to utilize a three-level fair value hierarchy that prioritizes the inputs used to measure fair value. The three levels of inputs used to measure fair value are as follows: Level 1 —Quoted prices in active markets for identical assets or liabilities. Financial assets and liabilities measured using Level 1 inputs include cash equivalents, restricted cash, accounts receivable, prepaid expenses and other current assets, accounts payable and accrued liabilities. The Company considers all highly liquid investments purchased with an original or remaining maturity of three months or less at the date of purchase to be cash equivalents. The Company measured money market funds of $71.8 million and $51.7 million as cash equivalents as of December 31, 2020 and 2019, respectively, using Level 1 inputs. Level 2 —Observable inputs other than quoted prices included within Level 1, including quoted prices for similar assets or liabilities in active markets; quoted prices for identical or similar assets or liabilities in markets that are not active; and inputs other than quoted prices that are observable or are derived principally from, or corroborated by, observable market data by correlation or other means. The Company did not have any Level 2 instruments as of December 31, 2020 and 2019. Level 3 —Unobservable inputs that are supported by little or no market activity, are significant to the fair value of the assets or liabilities and reflect the Company’s own assumptions about the assumptions market participants would use in pricing the asset or liability developed based on the best information available in the circumstances. The Company did not have Level 3 instruments at December 31, 2020 and 2019. Assets and liabilities that are measured at fair value on a non-recurring basis Non-financial assets such as goodwill, intangible assets, property, plant, and equipment, operating lease right-of-use assets and licensed content assets are evaluated for impairment and adjusted to fair value using Level 3 inputs, only when impairment is recognized. The impairments for operating ROU assets recorded by the Company for the years ended December 31, 2020 and 2019 were not material.

Leases

Leases	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Leases	9. LEASES The Company has entered into operating leases primarily for office real estate. The leases have remaining terms ranging from one year to 10 years and may include options to extend or terminate the lease. The components of lease expense are as follows (in thousands): Years Ended December 31, 2020 2019 Operating lease cost (1) $ 56,348 $ 35,146 Sublease income (2,105 ) (2,622 ) Net operating lease cost $ 54,243 $ 32,524 (1) For the years ended December 31, 2020 and 2019, variable lease costs were $12.1 million and $4.9 million, respectively. Variable lease costs primarily include common area maintenance charges. Supplemental cash flow information related to leases is as follows (in thousands): Years Ended December 31, 2020 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash outflows from operating leases $ 30,664 $ 17,721 Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 12,031 $ 267,048 Supplemental balance sheet information related to leases was as follows (in thousands, except lease term and discount rate): As of December 31, 2020 2019 Operating lease right-of-use assets $ 266,197 $ 283,291 Included in accounts payable and accrued liabilities: Operating lease liability, current 35,647 17,896 Operating lease liability, non-current 307,936 301,694 Total operating lease liability $ 343,583 $ 319,590 Weighted Average Remaining Lease Term: Operating leases (in years) 9.05 9.98 Weighted Average Discount Rate: Operating leases 4.60 % 4.65 % Future lease payments under operating leases as of December 31, 2020 were as follows (in thousands): Year Ending December 31, Operating Leases 2021 $ 50,889 2022 47,377 2023 47,597 2024 46,635 2025 46,295 Thereafter 201,852 Total future lease payments 440,645 Less: imputed interest (81,076 ) Less: expected tenant improvement allowance (15,986 ) Total $ 343,583 As of December 31, 2020, the Company’s commitment relating to the operating lease that has not yet commenced is $2.7 million. This operating lease commences in fiscal year 2025 and has a lease term of two years.

Debt

Debt	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Debt	10. DEBT The Company’s outstanding debt as of December 31, 2020 and 2019 is as follows (in thousands): As of December 31, 2020 2019 Amount Effective Interest Rate Amount Effective Interest Rate Term Loan A Facility $ 95,000 2.03 % $ 100,000 3.48 % Less: Debt issuance costs (258 ) (392 ) Net carrying amount of debt $ 94,742 $ 99,608 The carrying amount of debt approximates fair value due to its variable interest rates. The interest expense for the years ended December 31, 2020 and 2019 relating to the Credit Agreement is $2.6 million and $0.4 million, respectively. Senior Secured Term Loan A and Revolving Credit Facilities On February 19, 2019 (the “Original Closing Date”), the Company entered into a Credit Agreement (the “Existing Credit Agreement”) with Morgan Stanley Senior Funding, Inc. On May 3, 2019, (the “Closing Date”), the Existing Credit Agreement was amended pursuant to an Incremental Assumption and Amendment No. 1 (the “Amendment” and the Existing Credit Agreement as amended by the Amendment, the “Credit Agreement”). On the Original Closing Date, the Company terminated the Amended and Restated Loan and Security Agreement that it entered into with Silicon Valley Bank in November 2014 (the “Restated 2014 LSA”). The Credit Agreement provides for (i) a four-year four-year On November 18, 2019, the Company borrowed the Term Loan A facility in the aggregate principal amount of $100.0 million. In March 2020, the Company borrowed the available balance of $69.3 million from the Revolving Credit Facility. For both borrowings, the Company elected an interest rate equal to the adjusted one-month LIBOR rate plus an applicable margin of 1.75% based on the Company’s secured leverage ratio. In May 2020, the Company repaid the outstanding balance on the Revolving Credit Facility. Loans under the Term Loan A Facility amortize in equal quarterly installments beginning on March 31, 2020, in an aggregate annual amount equal to (i) on or prior to December 31, 2021, 1.25% of the drawn principal amount of the Term Loan Facility or $1.25 million and (ii) thereafter, 2.50% of the drawn principal amount of the Term Loan Facility or $2.5 million, with the remaining balance payable on the maturity date of the Term Loan A Facility in February 2023. The Company had outstanding letters of credit against the Revolving Credit Facility of $30.8 million and $30.7 million as of December 31, 2020 and December 31, 2019, respectively. The Company’s obligations under the Credit Agreement are secured by substantially all of its assets. In the future, certain of its direct and indirect subsidiaries may be required to guarantee the Credit Agreement. The Company may prepay, and in certain circumstances would be required to prepay, loans under the Credit Agreement without payment of a premium. The Credit Agreement contains customary representations and warranties, customary affirmative and negative covenants, a financial covenant that is tested quarterly and requires the Company to maintain a certain adjusted quick ratio of at least 1.00 to 1.00, and customary events of default. As of December 31, 2020, the Company was in compliance with all of the covenants of the Credit Agreement.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Stockholders' Equity	11. STOCKHOLDERS’ EQUITY Preferred Stock The Company has 10 million shares of undesignated preferred stock authorized but not issued with rights and preferences determined by the Company’s Board of Directors at the time of issuance of such shares. As of December 31, 2020 and 2019, there were no shares of preferred stock issued and outstanding. Common Stock The Company has two At-the-Market Offering On May 13, 2020, the Company entered into an Equity Distribution Agreement with Morgan Stanley & Co. LLC and Citigroup Global Markets Inc., as its sales agents, pursuant to which the Company sold an aggregate of 4.0 million shares of the Company’s Class A common stock and received gross proceeds of $504.0 million at an average selling price of $126.01 per share and incurred issuance costs of $6.8 million. Common Stock Reserved For Issuance At December 31, 2020, the Company had reserved shares of common stock for issuance as follows (in thousands): As of December 31, 2020 Common stock awards granted under equity incentive plans 13,088 Common stock awards available for issuance under the 2017 Employee Stock Purchase Plan * 5,089 Common stock awards available for issuance under the 2017 Equity Incentive Plan 21,420 Total reserved shares of common stock 39,597 * The Company has not issued any common stock pursuant to the 2017 Employee Stock Purchase Plan. Equity Incentive Plans The Company has two equity incentive plans, the 2008 Equity Incentive Plan (the “2008 Plan”) and the 2017 Equity Incentive Plan (the “2017 Plan”). The 2017 Plan became effective September 2017 in connection with the IPO. No further shares have been issued under the 2008 Plan. The 2017 Plan provides for the grant of incentive stock options to the Company’s employees and for the grant of non-statutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance stock awards, performance cash awards, and other forms of equity compensation to the Company’s employees, directors and consultants. Restricted stock units granted under the plan are subject to continuous service. Options granted under the plans are granted at a price per share equivalent to the fair market value on the date of grant. Recipients of option grants 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 are at a price no less than 110% of the fair market value at the date of grant. Restricted Stock Units Restricted stock unit activity for the year ended December 31, 2020 is as follows (in thousands, except per share data): Number of Shares Weighted Average Grant Date Fair Value Per Share Balance, December 31, 2019 4,544 $ 67.30 Awarded 1,425 147.46 Released (1,253 ) 66.79 Forfeited (361 ) 76.55 Balance, December 31, 2020 - outstanding 4,355 $ 92.91 The grant-date fair value of restricted stock units granted during the years ended December 31, 2020, 2019 and 2018 was $210.1 million, $195.2 million and $184.7 million, respectively. The fair value of restricted stock units that vested during the years ended December 31, 2020, 2019 and 2018 was $ million, $ million and $11.4 million, respectively. Total unrecognized compensation cost related to restricted stock units awarded to employees as of December 31, 2020 was $336.4 million, which the Company expects to recognize over 2.26 years. Stock options The following table summarizes the Company’s stock option activities under the 2008 Plan and 2017 Plan (in thousands, except per share data): Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Life (Years) Weighted Average Grant Date Fair Value Per Share Aggregate Intrinsic Value Balance, December 31, 2019 11,124 $ 14.84 6.2 — Granted 599 145.17 — $ 54.39 Exercised (2,854 ) 5.89 — — Forfeited and expired (136 ) 48.04 — — Balance, December 31, 2020 - outstanding 8,733 $ 26.19 5.7 — $ 2,670,743 Options exercisable at December 31, 2020 6,144 $ 8.00 4.8 — $ 1,990,694 The weighted average grant-date fair value of options granted during the years ended December 31, 2020, 2019 and 2018 was $54.39, $39.23 and $22.96, respectively. The intrinsic value for options exercised in the years ended December 31, 2020, 2019 and 2018 was $470.8 million, $474.2 million and $445.9 million, respectively. Intrinsic value represents the difference between the fair values of the Company’s common stock and the options’ exercise price on the date of grant. As of December 31, 2020, the Company had $50.8 million of unrecognized stock compensation expense related to unvested stock options that is expected to be recognized over a weighted-average period of approximately 1.78 years. Stock-based Compensation The Company measures the cost of employee services received in exchange for an equity award based on the grant date fair value of the award. Generally, stock options granted to employees vest 25% after one year and then 1/48th monthly thereafter and have a term of ten years. Restricted stock units generally vest over 4 years. For the years ended December 31, 2020, 2019, and 2018, the amount of stock-based compensation capitalized as part of internal use software was not material. The following table shows total stock-based compensation expense for the years ended December 31, 2020, 2019 and 2018 (in thousands): Years Ended December 31, 2020 2019 2018 Cost of platform revenue $ 847 $ 342 $ 97 Cost of player revenue 1,407 1,072 469 Research and development 58,412 40,036 18,538 Sales and marketing 42,846 24,179 10,459 General and administrative 30,564 19,546 8,111 Total stock-based compensation $ 134,076 $ 85,175 $ 37,674 The fair value of options granted under the 2008 Plan and 2017 Plan is estimated on the grant date using the Black-Scholes option-valuation model. This valuation model for stock-based compensation expense requires the Company to make certain assumptions and judgments about the variables used in the calculation, including the expected term, the expected volatility of the Company’s common stock, an assumed risk-free interest rate, and expected dividends. The Company uses the straight-line method for expense recognition. The Company recognizes forfeitures as they occur. Fair Value of Common Stock: T he Company uses the market closing price for the Class A common stock as reported on The Nasdaq Global Select Market on the date of grant. 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, . 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 options. Where the expected term of the Company’s stock options does not correspond with the term for which an interest rate is quoted, the Company performs a straight-line interpolation to determine the rate from the available term maturities. The assumptions used to value stock options granted during the years ended December 31, 2020, 2019 and 2018 are as follows: Years Ended December 31, 2020 2019 2018 Expected term (in years) 5.0 - 6.7 5.0 - 6.7 5.3 - 6.8 Risk-free interest rate 0.22 - 1.67% 1.35 - 2.56% 2.32 - 2.88% Expected volatility 36 - 39% 35 - 36% 38 - 40% Dividend rate — — —

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	12. COMMITMENTS AND CONTINGENCIES Manufacturing Purchase Commitments The Company has various manufacturing contracts with vendors in the conduct of the normal course of its business. In order to manage future demand for its products, the Company enters into agreements with manufacturers and suppliers to procure inventory based upon certain criteria and timing. Some of these commitments are non-cancelable. The Company records a liability for non-cancelable purchase commitments in excess of projected demand forecasts. License Content Commitments As of December 31, 2020, the Company recognized a liability of $6.2 million in Accrued liabilities and $1.4 million in Other long-term liabilities for licensed content that is available for streaming. As of December 31, 2019, the Company recorded $1.7 million as obligations in Accrued liabilities for licensed content that is available for streaming. The increase in content liability is due to change in the mix of content licensed and the period over which this content is available for streaming. The Company also enters into contracts with content publishers to acquire content or to buy ad inventory in the future. for streaming and is recognized as liabilities as well as content that is not yet available for streaming or ad inventories not yet purchased. Letters of Credit As of December 31, 2020 and 2019, the Company had irrevocable letters of credit outstanding in the amount of $30.9 million and $31.8 million, respectively, related to facilities leases. The letters of credit have various expiration dates through 2030. Contingencies The Company accrues for loss contingencies, including liabilities for intellectual property licensing claims, when it believes such losses are probable and reasonably estimable. As of December 31, 2020, the Company does not have any loss contingencies that are material. During the year ended December 31, 2019, the Company recorded expenses of $9.9 million, in total cost of revenue, for various claims related to patent infringements. During the year ended December 31, 2018, the Company changed its estimate of certain liabilities previously recorded for intellectual property licensing and released $8.9 million as a result of its assessment that the likelihood of payment is now remote. The reversal of $8.9 million is recorded within cost of revenue, player during the year ended December 31, 2018, in the consolidated statements of operations. From time to time, the Company is subject to legal proceedings, claims, and investigations in the ordinary course of business, including claims relating to employee relations, business practices and patent infringement. The Company is involved in litigation matters not listed herein. Although the results of these proceedings, claims, and investigations cannot be predicted with certainty, the Company does not believe that the final outcome of any matters that it is currently involved in are reasonably likely to have a material adverse effect on its business, financial condition, or results of operations. Indemnification In the ordinary course of business, the Company has entered into contractual arrangements which provide indemnification provisions of varying scope and terms to business partners and other parties with respect to certain matters, including, but not limited to, losses arising out of the Company’s breach of such agreements and out of intellectual property infringement claims made by third parties. 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.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	13. INCOME TAXES The components of loss before income taxes consist of the following (in thousands): Years Ended December 31, 2020 2019 2018 United States $ (21,107 ) $ (63,453 ) $ (11,128 ) Foreign 2,655 2,534 1,795 Net loss before income taxes $ (18,452 ) $ (60,919 ) $ (9,333 ) The income tax (benefit) expense consisted of the following (in thousands): Years Ended December 31, 2020 2019 2018 Current: Federal $ (219 ) $ (47 ) $ — State 620 244 114 Foreign 743 108 184 1,144 305 298 Deferred: Foreign (2,089 ) (1,287 ) (774 ) Total $ (945 ) $ (982 ) $ (476 ) The following is a reconciliation of the statutory federal income tax rate to the Company’s effective tax rate: Years Ended December 31, 2020 2019 2018 U.S. federal income tax at statutory rate 21.0 % 21.0 % 21.0 % U.S. state and local income taxes (3.2 ) (0.4 ) (1.3 ) Change in valuation allowance (698.4 ) (213.4 ) (1,039.4 ) Federal research and development tax credit 102.9 30.8 166.2 Stock-based compensation 577.8 158.0 859.4 Meals and Entertainment (1.6 ) (1.4 ) (6.6 ) Permanent items — — (1.1 ) Foreign rate differential — (0.6 ) (1.5 ) Acquisition costs — (1.3 ) — Section 162(m) limitation (7.2 ) (1.4 ) — State apportionment change 4.4 1.3 — Tax rate change — (0.4 ) 2.4 Provision to return true-up 9.4 9.9 5.9 Other 0.1 (0.5 ) 0.1 Effective tax rate 5.2 % 1.6 % 5.1 % Significant components of the Company’s deferred income tax assets and liabilities consist of the following (in thousands): As of December 31, 2020 2019 Deferred tax assets: Net operating loss carryforwards $ 379,613 $ 263,512 Reserves and accruals 14,131 10,425 Research and development credits 104,110 73,442 Lease Obligation 91,373 81,639 Stock-based compensation 28,318 17,494 Total deferred tax assets 617,545 446,512 Deferred tax liabilities: Right-of-use asset (70,755 ) (72,243 ) Depreciation and amortization (11,707 ) (10,916 ) Total deferred tax liabilities (82,462 ) (83,159 ) Valuation allowance (530,887 ) (361,233 ) Net deferred tax assets $ 4,196 $ 2,120 A valuation allowance is provided when it is more likely than not that some portion of the deferred tax assets will not be realized through future operations. As a result of the Company’s analysis of all available objective evidence, both positive and negative, as of December 31, 2020, management believes it is more likely than not that the U.S. deferred tax assets will not be fully realizable. Accordingly, the Company has provided a full valuation allowance against its U.S. deferred tax assets. The Company's valuation allowance increased by $169.7 million and $178.9 million during the years ended December 31, 2020 and 2019, respectively, primarily due to U.S. federal and state tax losses and credits incurred during the period. For federal and state income tax reporting purposes, respective net operating loss carryforwards of $1,423.1 million and $1,273.9 million are available to reduce future taxable income, if any. These net operating loss carryforwards will begin to expire in 2028 for federal and certain state net operating losses have expired in 2020. The federal net operating loss generated subsequent to 2017 can be carried forward indefinitely. For U.K. and Denmark income tax reporting purposes, the net operating loss carryforward of $17.6 million and $0.8 million, respectively, is available to reduce the future taxable income, if any. U.K. and Denmark net operating loss can be carried forward indefinitely. The Company also has U.K. research and development tax credit carryforwards of $0.3 million. The credit can be carried forward indefinitely. As of December 31, 2020, the Company has research and development tax credit carryforwards of $82.6 million and $59.4 million for federal and state income tax purposes, respectively. If not utilized, the federal and state carryforwards will begin to expire in 2028 and 2035, respectively. The Internal Revenue Code of 1986, as amended (the “Code”), contains provisions that may limit the net operating loss and credit carryforwards available for use in any given period upon the occurrence of certain events, including a statutorily defined significant change in ownership. Utilization of the net operating loss and tax credit carryforwards is subject to an annual limitation due to an ownership change, as defined by section 382 of the Code. The Company has assessed whether any section 382 ownership change has occurred since its formation and determined that a section 382 ownership change occurred on December 18, 2009 and tax attributes generated by the Company through the ownership change date are subject to the limitation. A section 382 study was completed for dataxu covering the period from inception beginning May 1, 2008 through acquisition date of November 8, 2019. Based on the study, the Company identified four ownership changes for Section 382 purposes. As such, tax attributes generated by dataxu through the ownership change dates are subject to the limitation. The total amount of unrecognized tax benefits as of December 31, 2020 is $29.2 million, of which $28.3 million is composed of research and development credits and $0.9 million is related international activities. A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands): As of December 31, 2020 2019 Unrecognized tax benefits at beginning of year $ 19,487 $ 14,541 Gross increase for tax positions of current year 9,959 10,378 Gross decrease due to statue expiration (75 ) (88 ) Gross decrease for tax positions of prior years (196 ) (5,344 ) Unrecognized tax benefits balance at end of year $ 29,175 $ 19,487 The Company recognizes interest and penalties related to unrecognized tax benefits as a component of its income tax expense. As of December 31, 2020, the Company recorded $0.2 million of accrued interest and penalties related to uncertain tax positions. Change in the Company’s unrecognized tax benefits, if any, would have an immaterial impact on its effective tax rate. The Company does not expect its gross unrecognized tax benefits to change significantly within the next 12 months. The Company files income tax returns in the U.S. federal jurisdiction and various state jurisdictions. The Company is currently under examination by Texas Comptroller for calendar tax years 2015, 2016, and 2017. All tax years remain subject to examination by federal and state authorities. These audits include questioning the timing and amount of deductions; the nexus of income among various tax jurisdictions; and compliance with federal, state, and local tax laws. The Company will continue to indefinitely reinvest earnings from its foreign subsidiaries, which are not significant. While federal income tax expense has been recognized as a result of the Tax Cuts and Jobs Act of 2017, the Company has not provided any additional deferred taxes with respect to items such as foreign withholding taxes, state income tax or foreign exchange gain or loss. It is not practicable for the Company to determine the amount of unrecognized tax expense on these reinvested international earnings.

Related-Party Transactions

Related-Party Transactions	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Related-Party Transactions	14. RELATED-PARTY TRANSACTIONS The Company did not engage in any material related party transactions for the year ended December 31, 2020. There were no material amounts payable to or receivable from related parties as of December 31, 2020. In prior years, the Company engaged in transactions with one of its strategic investors. With respect to this investor, the Company recorded revenue of $8.5 million and $4.1 million for the years ended December 31, 2019 and 2018, respectively. The Company had an accounts receivable balance of $2.4 million as of December 31, 2019 related to transactions with this investor. The Company incurred expenses of $1.3 million and $1.3 million with this investor for the years ended December 31, 2019 and 2018, respectively. The Company had a payable of $0.4 million to this investor as of December 31, 2019. In addition, the Company had engaged in transactions with another company in which the Company’s Chief Executive Officer holds a majority voting interest and is a member of such company’s board of directors, and another member of the Company’s Board of Directors is such company’s Chief Executive Officer. With respect to transactions with this other company, the Company incurred expenses of $1.2 million for the year ended December 31, 2019. There were no outstanding amounts payable to this other company as of December 31, 2019. The Company did not consummate any transactions with the other company for the year ended December 31, 2018.

Retirement Plans

Retirement Plans	12 Months Ended
	Dec. 31, 2020
Compensation And Retirement Disclosure [Abstract]
Retirement Plans	15. RETIREMENT PLANS The Company maintains a 401(k) tax deferred saving plan (the “Savings Plan”) for the benefit of qualified employees. Qualified employees may elect to make contributions to the Savings Plan on a biweekly basis, subject to certain limitations. The Company may make contributions to the Savings Plan at the discretion of the Board of Directors. No contributions were made for the years ended December 31, 2020, 2019 and 2018. In 2014, the Company established a defined contribution plan in the U.K. for its U.K.-based employees. The Company contributed $0.7 million, $0.5 million and $0.4 million to the plan for the years ended December 31, 2020, 2019 and 2018, respectively.

Net Loss Per Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Net Loss Per Share	16. NET LOSS PER SHARE The Company’s basic net loss per share is calculated by dividing the net loss 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 options to purchase common stock, restricted stock units and unvested shares of common stock issued upon the early exercise of stock options and business acquisitions are considered common stock equivalents, but have been excluded from the calculation of diluted net loss per share as their effect is antidilutive. Because the Company has reported a net loss for the years ended December 31, 2020, 2019 and 2018, diluted net loss per common share is the same as the basic net loss per share for those years. The table presents the calculation of basic and diluted net loss per share as follows (in thousands, except per share data): Years Ended December 31, 2020 2019 2018 Numerator: Net loss attributable to common stockholders $ (17,507 ) $ (59,937 ) $ (8,857 ) Denominator: Weighted-average shares used in computing net loss per share, basic and diluted 123,978 115,218 104,618 Net loss per share, basic and diluted $ (0.14 ) $ (0.52 ) $ (0.08 ) The potential common shares that were excluded from the calculation of diluted net loss per share because their effect would have been antidilutive for the periods presented are as follows (in thousands): Years Ended December 31, 2020 2019 2018 Equity awards to purchase common stock 13,088 15,668 20,057 Unvested shares of common stock issued upon early exercise of stock options and business acquisition 1 31 70 Total 13,089 15,699 20,127

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Segment Information	17. 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’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. The Company uses the management approach to determine the segment financial information that should be disaggregated and presented separately in the Company’s notes to its consolidated financial statements. The management approach is based on the manner by which management has organized the segments within the Company for making operating decisions, allocating resources, and assessing performance. The Company reports its financial results consistent with the manner in which financial information is viewed by management for decision-making purposes. The Company does not manage operating expenses such as research and development, sales and marketing and general and administrative expenses at the segment level. The Company is organized into two reportable segments as follows: Platform Consists of revenue generated from sale of digital advertising, content distribution services, subscription and transaction revenue share including Premium Subscriptions, sale of branded buttons on remote controls and licensing arrangements with service operators and TV brands. Player Consists of revenue generated from sale of streaming players, audio products and accessories through retailers and distributors, as well as directly to customers through the Company’s website. The Company does not allocate property and equipment or any other assets or capital expenditures to reportable segments. Operating expenses are not managed at the segment level. The Company evaluates the performance of its reportable segments based on the financial measures, including segment gross profit, which are regularly reviewed by the CODM and provide insight into the individual segments and their ability to contribute to Company’s operating results. Customers accounting for 10% or more of segment revenue, net, were as follows: Years Ended December 31, 2020 2019 2018 Platform segment revenue Customer H 13 % * * Player segment revenue Customer A 10 % 16 % 15 % Customer B 18 % 17 % 15 % Customer C 40 % 39 % 38 % Revenue in international markets was less than 10% in each of the periods presented. Substantially all Company assets were held in the United States and were attributable to the operations in the United States as of December 31, 2020 and 2019.

Quarterly Financial Data (Unaud

Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data (Unaudited)	18. QUARTERLY FINANCIAL DATA (Unaudited) The following table summarizes the Company’s information on total revenue, gross profit, net income (loss) and earnings per share by quarter for the years ended December 31, 2020 and 2019. This data was derived from the Company’s unaudited consolidated financial statements (in thousands, except per share data): Three Months Ended Dec 31, 2020 Sep 30, 2020 Jun 30, 2020 Mar 31, 2020 Total Revenue $ 649,886 $ 451,663 $ 356,073 $ 320,766 Gross Profit 305,458 214,824 146,836 141,101 Net income (loss) attributable to common stockholders 67,306 12,947 (43,148 ) (54,612 ) Basic net income (loss) per share attributable to common stockholders 0.53 0.10 (0.35 ) (0.45 ) Diluted net income (loss) per share attributable to common stockholders 0.49 0.09 (0.35 ) (0.45 ) Three Months Ended Dec 31, 2019 Sep 30, 2019 Jun 30, 2019 Mar 31, 2019 Total Revenue $ 411,230 $ 260,928 $ 250,101 $ 206,662 Gross Profit 161,647 118,477 114,209 100,891 Net loss attributable to common stockholders (15,717 ) (25,155 ) (9,333 ) (9,732 ) Basic and diluted net loss per share attributable to common stockholders (0.13 ) (0.22 ) (0.08 ) (0.09 )

Significant Accounting Polici_2

Significant Accounting Policies and Basis of Presentation (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation The consolidated financial statements, which include the accounts of Roku, Inc. and its wholly-owned subsidiaries, have been prepared in conformity with accounting principles generally accepted in the United States (“U.S. GAAP”). All intercompany accounts and transactions have been eliminated in consolidation.
Reclassification of Prior Year Presentation	Reclassification of Prior Year Presentation Certain prior period amounts within cash flow from operations in the statement of cash flows, have been reclassified to conform to current period presentation. These reclassifications had no effect on net cash provided by operating activities for any period reported.
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, judgements, and assumptions that affect the reported amounts of assets, liabilities, net revenue and expenses. Significant items subject to such estimates and assumptions include: for revenue recognition, determining the nature and timing of satisfaction of performance obligations, variable consideration, determining the stand-alone selling prices of performance obligations, gross versus net revenue recognition, evaluation of customer versus vendor relationships, and other obligations such as sales return reserves and sales incentive programs; the impairment of goodwill and intangible assets; useful lives of tangible and intangible assets; allowances for doubtful accounts; the valuation of deferred income tax assets; and stock-based compensation. 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 and assumptions.
Comprehensive Loss	Comprehensive Loss The comprehensive loss is equal to the net loss for the year ended December 31, 2020. Comprehensive loss includes unrealized gains on the Company’s short-term investments and foreign currency translation adjustments for the year ended December 31, 2019. Comprehensive loss includes unrealized losses on the Company’s short-term investments for the year ended December 31, 2018. Income taxes on the unrealized gains or losses are not material.
Foreign Currency	Foreign Currency The functional currency of the Company’s foreign subsidiaries is the U.S. dollar. Monetary assets and liabilities of these subsidiaries are remeasured into U.S. dollars from the local currency at rates in effect at period-end and nonmonetary assets and liabilities are remeasured at historical rates. Revenues and expenses are remeasured at average exchange rates in effect during each period. Foreign currency gains or losses from re-measurement and transaction gains or losses are recorded as other income (expense), net in the consolidated statements of operations. During the year ended December 31, 2020, the Company recorded a foreign currency gain of $1.3 million. During the years ended December 31, 2019 and 2018, the Company recorded a foreign currency loss of $0.2 million and $0.5 million, respectively.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. As of December 31, 2020, two financial institutions managed 46% and 26%, respectively, of the Company’s total cash and cash equivalents balance. As of December 31, 2019, the same two financial institutions managed 65% and 34%, respectively, of the Company’s total cash and cash equivalents balance.
Accounts Receivable, Net	Accounts Receivable, net Accounts receivable are typically unsecured and are derived from revenue earned from customers. They are stated at invoice value less estimated allowances for sales returns, sales incentives and doubtful accounts. The Company performs ongoing credit evaluations of its customers and maintains allowances for potential credit losses and doubtful accounts. The Company considers historical experience, ongoing promotional activities, historical claim rate and other factors to determine the allowances for sales returns and sales incentives. Allowance for Sales Returns : Allowance for sales returns consist of the following activities (in thousands): Years Ended December 31, 2020 2019 2018 Beginning balance $ (6,550 ) $ (7,335 ) $ (6,907 ) Charged to revenue (14,594 ) (15,541 ) (17,396 ) Utilization of sales return reserve 15,232 16,326 16,968 Ending balance $ (5,912 ) $ (6,550 ) $ (7,335 ) Allowance for Sales Incentives : Allowance for sales incentives consisted of the following activities (in thousands): Years Ended December 31, 2020 2019 2018 Beginning balance $ (19,476 ) $ (13,750 ) $ (10,442 ) Charged to revenue (68,315 ) (65,676 ) (50,958 ) Utilization of sales incentive reserve 56,953 59,950 47,650 Ending balance $ (30,838 ) $ (19,476 ) $ (13,750 ) Allowance for Doubtful Accounts : Allowance for doubtful accounts consisted of the following activities (in thousands): Years Ended December 31, 2020 2019 2018 Balance, beginning of period $ (1,140 ) (686 ) (63 ) Impact of adoption of ASU 2016-13 (1,066 ) — — Adjusted balance, beginning of period (2,206 ) (686 ) (63 ) Provision for doubtful accounts $ (3,801 ) $ (704 ) $ (876 ) Adjustments for recovery and write-off 1,826 250 253 Balance, end of period (4,181 ) (1,140 ) (686 ) Customer H accounted for 11% of the accounts receivable, net balance as of December 31, 2020. The Company did not have any customer that accounted for more than 10% of its accounts receivable, net balance as of December 31, 2019.
Business Combinations	Business Combinations The Company determines whether a transaction meets the definition of a business combination before applying the acquisition method of accounting to that transaction. The Company allocates the fair value of the purchase consideration of its acquisitions to the tangible and intangible assets acquired and liabilities assumed, based on their estimated fair values. The excess of the fair value of purchase consideration over the fair values of identifiable assets and liabilities is recorded as goodwill. The operating results of acquired business is included in the Company’s consolidated statement of operations beginning on their effective acquisition date. Acquisition-related expenses and certain acquisition restructuring and other related charges are recognized separately from the business combination and are expensed as incurred. Contingent consideration arrangements are recognized at fair value as of the acquisition date with subsequent fair value adjustments recorded in operations. While the Company uses its best estimates and assumptions to accurately value assets acquired and liabilities assumed at the acquisition date, estimates are inherently uncertain and subject to refinement. As a result, during the measurement period, which may be up to one year from the acquisition date, the Company may record adjustments to the assets acquired and liabilities assumed with the corresponding offset to goodwill. In addition, uncertain tax positions and tax-related valuation allowances are initially recorded in connection with a business combination as of the acquisition date. The Company continues to collect information and reevaluates these estimates and assumptions quarterly and records any adjustments to the Company’s preliminary estimates to goodwill provided that the Company is within the measurement period. Upon the conclusion of the measurement period or final determination of the values of assets acquired or liabilities assumed, whichever comes first, any subsequent adjustments are recorded to our consolidated statements of operations.
Intangible Assets	Intangible Assets Intangible assets acquired through business combinations are recorded at their fair values upon acquisition close. Intangible assets are amortized using the straight-line method over their estimated useful lives. The Company evaluates the estimated remaining useful lives of its intangible assets annually and when events or changes in circumstances warrant a revision to the remaining periods of amortization.
Impairment Assessment	Impairment Assessments The Company evaluates goodwill for possible impairment at least annually during the fourth quarter of each fiscal year or more often, if and when circumstances indicate that goodwill may be impaired. This includes but is not limited to significant adverse changes in the business climate, market conditions, or other events that indicate that it is more likely than not that the fair value of a reporting unit is less than its carrying value. In performing its annual assessment, the Company can opt to perform a qualitative assessment to test a reporting unit’s goodwill for impairment or it can directly perform a quantitative assessment. Based on the Company’s qualitative assessment, if it is determined that the fair value of our reporting unit is, more likely than not, less than its carrying amount, then the quantitative assessment is performed. Any excess of the reporting unit's carrying amount over its fair value is be recorded as an impairment loss. The Company reviews long-lived assets, intangible assets and capitalized licensed content assets with finite lives for impairment when events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable or that the useful lives of those assets are no longer appropriate. The Company assesses these assets for impairment based on their estimated undiscounted future cash flows. If the carrying value of the asset group exceeds the estimated future undiscounted cash flows, the Company recognizes an impairment loss based on the excess of the carrying amount over the fair value of the asset group. The Company did not recognize any impairment for goodwill, intangible assets or capitalized licensed content assets in any periods reported. The impairments of operating right-of-use assets during the years ended December 31, 2020 and 2019 were not material.
Revenue Recognition	Revenue Recognition Revenue is recognized upon transfer of control of promised goods or services to customers in an amount that reflects the consideration the Company expects to receive in exchange for those goods or services. The Company’s contracts include various product or services or a combination of both, which are generally capable of being distinct and are accounted for as separate performance obligations. The Company’s contracts often contain multiple distinct performance obligations. The Company estimates the transaction price of a contract based on the expected value for which a significant reversal of revenue is not expected to occur. The estimate of the variable consideration is based on the assessment of historical, current, and forecasted performance noted and expected from the performance obligation. In arrangements with multiple performance obligations, the estimated transaction price of each contract is allocated to each distinct performance obligation based on relative stand-alone selling price (“SSP”). For performance obligations routinely sold separately, the SSP is determined by evaluating such stand-alone sales. For those performance obligations that are not routinely sold separately, the Company determines SSP based on market conditions and other observable inputs. When the Company sells third-party goods and services, it evaluates whether the Company is the principal, and reports revenues on a gross basis, or an agent, and reports revenues on a net basis. In this assessment, the Company considers if it obtains control of the specified goods or services before they are transferred to the customer, as well as other indicators such as the party primarily responsible for fulfillment, inventory risk, and discretion in establishing price. Revenue is recorded net of taxes collected from customers which are subsequently remitted to the relevant government authority. The Company does not capitalize any cost associated with contract acquisition because it applies a practical expedient and expenses commissions when incurred as most direct contract acquisition costs relate to contracts that are recognized over a period of one year or less. Sales commissions are included in Sales and marketing expenses in the consolidated statements of operations. As-invoiced practical expedient is applied when the amount of consideration the Company has a right to invoice corresponds directly with the value to the customer of the entity’s performance completed to date. Nature of Products and Services Platform segment: The Company generates platform revenue from the sale of digital advertising and related services, content distribution services, subscription and transaction revenue shares, Premium Subscriptions, billing services, sale of branded channel buttons on remote controls and licensing arrangements with service operators and TV brands. The Company sells digital advertising directly to marketers or through advertising agencies. Revenue from advertising is mostly generated through video and display advertising delivered through advertising impressions. Advertising is typically sold on a cost-per-thousand (“CPM”) basis and is evidenced by an Insertion Order (“IO”). Revenue is recognized as the number of impressions are delivered. IOs may include multiple performance obligations as they contain distinct advertising products or services. For such arrangements, the Company allocates revenue to each distinct performance obligation based on their relative SSP. The Company also generates revenue from customers using its platform. For that it charges a platform fee, which is a percentage of a customer’s advertising inventory spend during the month, along with data and any add-on features purchased through the platform. The Company recognizes revenue on either a gross or net basis for digital advertising based on its determination as to whether it is acting as the principal in the revenue generation process or as an agent. Where the Company is the principal, it controls the advertising inventory before it is transferred to its customers. This is further supported by the Company being primarily responsible to its customers and having a level of discretion in establishing pricing. Advertising arrangements comprised of multiple performance obligations are recognized either at a point in time or over time depending on the nature of the distinct performance obligation. The Company’s content distribution revenue sharing arrangements include cash or non-cash consideration. The revenue sharing arrangements generally apply to new subscriptions for accounts that sign up for new services and at the time of a movie rental or purchase. Revenue is recognized on a net basis as the Company is deemed to be the agent between content publishers and end users. Revenue is recognized on a time elapsed basis, by day, as the services are delivered over the contractual distribution term. Non-cash consideration is usually in the form of advertising inventory, the fair value of which is determined based on relevant internal and third-party data. The Company sells monthly subscriptions for premium content on The Roku Channel for varying fees for different content. Revenue from such premium subscription fees is recognized on a gross basis over the service period as the Company is deemed to be the principal in the relationship with the end user. The Company obtains control of the content before transferring to the end user and has latitude in establishing pricing. The Company pays fixed fees to the providers of premium content on The Roku Channel based on the contractual arrangement and recognizes that in Cost of revenue, platform. The Company sells branded channel buttons on remote controls of streaming devices that provide one-touch access to a publisher’s content. The Company typically receives a fixed fee per button for each unit sold over a defined distribution period. Revenue is recognized on a time elapsed basis, by day, over the distribution term. The Company licenses the Roku OS, including updates and upgrades, to TV brands and service operators. The licensing revenue is recognized at a point in time, when the Company makes the intellectual property available and the control transfers to the customer. The revenue allocated to unspecified upgrades is recognized on a time elapsed basis, by day, over the service period. Professional services revenue is recognized as services are provided or accepted. Hosting fees are recognized on a time elapsed basis, by day, over the service period. Player segment: The Company sells the majority of its players and audio products to retail distribution channels in the U.S., including brick and mortar and online retailers, as well as through the Company’s website. Player revenue primarily consists of hardware, embedded software and unspecified upgrades on a when and if-available basis. The hardware and embedded software are considered as one performance obligation and revenue is recognized at a point in time when the control transfers to the customer. Unspecified upgrades or enhancements are available to customers on a when-and-if available basis. The Company records the allocated value of the unspecified upgrades as deferred revenue and recognizes it as player revenue ratably on a time elapsed basis over the estimated economic life of the associated players. The Company’s player revenue includes allowances for sales returns and sales incentives in the estimated transaction price. These estimates are based on historical experience and anticipated performance. Shipping charges billed to customers are included in Revenue and the related shipping costs are included in Cost of revenue.
Leases	Leases On January 1, 2019, the Company adopted the guidance in Leases (Topic 842), Operating leases are included in operating lease right-of-use assets, accrued liabilities, and operating lease liability in our consolidated balance sheets. represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent its obligation to make lease payments arising from the lease.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The Company defines fair value as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The Company applies fair value accounting for all assets and liabilities that are recognized or disclosed at fair value in the consolidated financial statements. The carrying amounts reported in the consolidated financial statements for cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities approximate their fair values due to their short-term nature. The carrying amount of debt approximates fair value due to its variable interest rates.
Inventories	Inventories The Company’s inventories consist primarily of finished goods and are stated at the lower of cost or net realizable value with cost determined on a first-in, first-out basis. Provisions are made if the cost of the inventories exceeds their net realizable value. The Company evaluates inventory levels and purchase commitments for excess and obsolete products, based on management’s assessment of future demand and market conditions.
Property and Equipment	Property and Equipment Property and equipment are recorded at cost and depreciated using the straight-line method over their estimated useful lives of the assets, generally ranging between eighteen months and five years The Company capitalizes costs to develop its internal-use software. Costs that relate to the planning and post-implementation phases of development are expensed as incurred. Costs are capitalized when preliminary efforts are successfully completed, management has authorized and committed to funding the project, and it is probable that the project will be completed and will be used as intended. Costs incurred for enhancements that are expected to result in additional material functionality are capitalized. During the years ended December 31, 2020, 2019 and 2018, the Company capitalized internal-use software development costs of $2.2 million, $0.1 million and $1.0 million, respectively. Capitalized costs are amortized using the straight-line method over the estimated useful life of the asset, which is generally two to three years, beginning when the asset is ready for its intended use. During the years ended December 31, 2020, 2019 and 2018, the Company amortized expenses of $0.5 million, $1.6 million and $2.0 million, respectively.
Deferred Revenue	Deferred Revenue The Company’s deferred revenue reflects fees received from licensing and service arrangements, including advertising, that will be recognized as revenue over time or as services are rendered. Deferred revenue balances consist of the amount of player sales allocated to unspecified upgrades or enhancements on a when-and-if available basis, licensing and services fees from service operators and TV brands, and payments from advertisers and content publishers. Deferred revenue expected to be realized within one year is classified as current liabilities and the remaining is recorded as noncurrent liabilities.
Advertising Costs	Advertising Costs Advertising costs are expensed when incurred and are included in Sales and marketing expense in the consolidated statements of operations. The Company incurred advertising costs of $7.1 million, $7.3 million and $3.0 million for the years December 31, 2020, 2019 and 2018, respectively.
Stock-Based Compensation	Stock-Based Compensation The Company measures compensation expense for all stock-based awards, including restricted stock units and stock options granted to employees, based on the estimated fair value of the award on the date of grant. For restricted stock units, the grant date fair value is based on the closing market price of the Company’s Class A common stock on the date of grant. The fair value of each stock option is estimated using the Black-Scholes option-pricing model. The Company accounts for forfeitures as they occur. Stock-based compensation is recognized on a straight-line basis over the requisite vesting period.
Income Taxes	Income Taxes The Company accounts for income taxes using an asset and liability approach. Deferred tax assets and liabilities are determined based on the difference between the consolidated financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to affect taxable income. Valuation allowances are established when necessary to reduce deferred tax assets to the amounts that are more likely than not to be realized.
Net Loss per Share	Net Loss per Share Since the Company was in a loss position for all periods presented, basic net loss per share is the same as diluted net loss per share for all periods as the inclusion of all potential common shares outstanding and potentially dilutive securities would have been anti-dilutive.
Recently Adopted Accounting Standards and Recent Accounting Standards Not Yet Adopted	Recently Adopted Accounting Standards In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standard Update (“ASU”) 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments . The guidance amended reporting of credit losses for assets held at amortized cost basis and available-for-sale debt securities to require that credit losses on available-for-sale debt securities be presented as an allowance rather than as a write-down. On January 1, 2020, the Company adopted this guidance using the modified retrospective adoption method and recorded a cumulative-effect adjustment to the beginning balance of accumulated deficit of approximately $1.1 million. The measurement of credit losses for newly recognized financial assets and subsequent changes in the allowance for credit losses are recorded in the statements of operations. This impact mainly relates to credit losses recognized on the Company’s doubtful accounts. As the Company did not have any available-for-sale debt securities as of the adoption date, there was no additional impact to accumulated deficit. In March 2019, the FASB issued ASU 2019-02, Entertainment—Films—Other Assets—Film Costs (Subtopic 926-20) and Entertainment—Broadcasters—Intangibles—Goodwill and Other (Subtopic 920-350): Improvements to Accounting for Costs of Films and License Agreements for Program Materials , in order to align the accounting for production costs of an episodic television series with the accounting for production costs of films by removing the content distinction for capitalization. ASU 2019-02 also requires that an entity reassess estimates of the use of a film in a film group and account for any changes prospectively. In addition, ASU 2019-02 requires that an entity test films and license agreements for program material for impairment at a film group level when the film or license agreements are predominantly monetized with other films and license agreements. On January 1, 2020 , the Company adopted the guidance in ASU 2019-02 . There was no material impact to the Company’s consolidated financial statements. The Company also adopted the following ASUs effective January 1, 2020, none of which had a material impact on the Company’s financial position or results of operations. ASU Description ASU 2018-15 Intangibles—Goodwill and Other—Internal-Use Software (Topic 350), Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract ASU 2018-13 Fair Value Measurements (Topic 820), Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement ASU 2017-04 Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment ASU2019-04 Codification Improvements to Topic 326, Financial Instruments—Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments ASU2020-02 Financial Instruments—Credit Losses (Topic 326) and Leases (Topic 842)—Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 119 and Update to SEC Section on Effective Date Related to Accounting Standards Update No. 2016-02, Leases (Topic 842) ASU2020-03 Codification Improvements to Financial Instruments In March 2020, FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting . This guidance provides optional expedients and exceptions for applying U.S. GAAP to contract modifications, hedging relationships, and other transactions that reference London Interbank Offered Rate (“LIBOR”) that is expected to be discontinued, subject to meeting certain criteria. The guidance is effective as of March 12, 2020 through December 31, 2022. The Company made a policy election in the second quarter of 2020 to elect a different reference rate for the Credit Agreement when LIBOR is discontinued. It is still uncertain when the transition from LIBOR to another reference rate will occur or which reference rate will become the accepted market alternative to LIBOR. Recent Accounting Standards Not Yet Adopted In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes
Fair Value Disclosure	The Company’s financial assets measured at fair value are as follows (in thousands): As of December 31, 2020 As of December 31, 2019 Fair Value Level 1 Fair Value Level 1 Assets: Cash and cash equivalents: Cash $ 1,021,022 $ 1,021,022 $ 463,820 $ 463,820 Money market funds 71,793 71,793 51,659 51,659 Restricted cash 434 434 1,854 1,854 Total assets measured and recorded at fair value $ 1,093,249 $ 1,093,249 $ 517,333 $ 517,333 Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in the principal market (or most advantageous market, in the absence of a principal market) for the asset or liability in an orderly transaction between market participants at the measurement date. Further, the Company maximizes the use of observable inputs and minimizes the use of unobservable inputs in measuring fair value, and to utilize a three-level fair value hierarchy that prioritizes the inputs used to measure fair value. The three levels of inputs used to measure fair value are as follows: Level 1 —Quoted prices in active markets for identical assets or liabilities. Financial assets and liabilities measured using Level 1 inputs include cash equivalents, restricted cash, accounts receivable, prepaid expenses and other current assets, accounts payable and accrued liabilities. The Company considers all highly liquid investments purchased with an original or remaining maturity of three months or less at the date of purchase to be cash equivalents. The Company measured money market funds of $71.8 million and $51.7 million as cash equivalents as of December 31, 2020 and 2019, respectively, using Level 1 inputs. Level 2 —Observable inputs other than quoted prices included within Level 1, including quoted prices for similar assets or liabilities in active markets; quoted prices for identical or similar assets or liabilities in markets that are not active; and inputs other than quoted prices that are observable or are derived principally from, or corroborated by, observable market data by correlation or other means. The Company did not have any Level 2 instruments as of December 31, 2020 and 2019. Level 3 —Unobservable inputs that are supported by little or no market activity, are significant to the fair value of the assets or liabilities and reflect the Company’s own assumptions about the assumptions market participants would use in pricing the asset or liability developed based on the best information available in the circumstances. The Company did not have Level 3 instruments at December 31, 2020 and 2019. Assets and liabilities that are measured at fair value on a non-recurring basis Non-financial assets such as goodwill, intangible assets, property, plant, and equipment, operating lease right-of-use assets and licensed content assets are evaluated for impairment and adjusted to fair value using Level 3 inputs, only when impairment is recognized. The impairments for operating ROU assets recorded by the Company for the years ended December 31, 2020 and 2019 were not material.

Significant Accounting Polici_3

Significant Accounting Policies and Basis of Presentation (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Schedule of Allowance for Sales Returns	Allowance for sales returns consist of the following activities (in thousands): Years Ended December 31, 2020 2019 2018 Beginning balance $ (6,550 ) $ (7,335 ) $ (6,907 ) Charged to revenue (14,594 ) (15,541 ) (17,396 ) Utilization of sales return reserve 15,232 16,326 16,968 Ending balance $ (5,912 ) $ (6,550 ) $ (7,335 )
Schedule of Allowance for Sales Incentives	Allowance for sales incentives consisted of the following activities (in thousands): Years Ended December 31, 2020 2019 2018 Beginning balance $ (19,476 ) $ (13,750 ) $ (10,442 ) Charged to revenue (68,315 ) (65,676 ) (50,958 ) Utilization of sales incentive reserve 56,953 59,950 47,650 Ending balance $ (30,838 ) $ (19,476 ) $ (13,750 )
Schedule of Allowance for Doubtful Accounts	Allowance for doubtful accounts consisted of the following activities (in thousands): Years Ended December 31, 2020 2019 2018 Balance, beginning of period $ (1,140 ) (686 ) (63 ) Impact of adoption of ASU 2016-13 (1,066 ) — — Adjusted balance, beginning of period (2,206 ) (686 ) (63 ) Provision for doubtful accounts $ (3,801 ) $ (704 ) $ (876 ) Adjustments for recovery and write-off 1,826 250 253 Balance, end of period (4,181 ) (1,140 ) (686 )

Revenue (Tables)

Revenue (Tables)	12 Months Ended
	Dec. 31, 2020
Revenue From Contract With Customer [Abstract]
Schedule of Contract Balances	The contract balances include the following (in thousands): As of December 31, 2020 2019 2018 Accounts receivable, net $ 523,852 $ 332,673 $ 183,078 Contract assets (included in Prepaid expenses and other current assets) 7,431 3,588 753 Deferred revenue, current portion 55,465 39,861 45,442 Deferred revenue, non-current portion 21,283 15,370 19,594 Total deferred revenue $ 76,748 $ 55,231 $ 65,036

Business Combination (Tables)

Business Combination (Tables)	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Schedule of Allocation of Purchase Consideration to Tangible and Intangible Assets Acquired and Liabilities Assumed on Acquisition Date	The allocation of the purchase consideration to tangible and intangible assets acquired and liabilities assumed on acquisition date is based on estimated fair values and is as follows (in thousands): Assets acquired Fair Values Estimated Useful Lives (in years) Current assets $ 50,829 Restricted cash 1,303 Property and equipment, net 4,503 Intangible assets: Developed Technology 56,400 6.0 Customer relationships 13,400 4.0 Tradename 400 0.5 Goodwill 71,676 Operating lease right-of-use assets 24,658 Other long-term assets 235 Total assets acquired 223,404 Liabilities assumed Current liabilities (51,428 ) Operating lease liabilities (24,658 ) Total liabilities assumed (76,086 ) Total purchase consideration $ 147,318

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2020
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of Carrying Value of Goodwill	The following table reflects the carrying value of goodwill (in thousands): Carrying Value Balance as of December 31, 2018 $ 1,382 Addition: dataxu acquisition 72,734 Balance as of December 31, 2019 74,116 Adjustment: dataxu working capital adjustments (1,058 ) Balance as of December 31, 2020 $ 73,058
Summary of Intangible Assets	The following table is the summary of Company’s intangible assets (in thousands): As of December 31, 2020 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted-Average Useful Lives (in years) Developed technology $ 62,367 $ (13,439 ) $ 48,928 5.9 Customer relationships 13,400 (3,908 ) 9,492 4.0 Tradename 400 (400 ) — 0.5 Patents 4,076 (315 ) 3,761 14.0 Intangible assets $ 80,243 $ (18,062 ) $ 62,181 As of December 31, 2019 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted-Average Useful Lives (in years) Developed technology $ 62,367 $ (2,860 ) $ 59,507 5.9 Customer relationships 13,400 (558 ) 12,842 4.0 Tradename 400 (133 ) 267 0.5 Patents 4,076 (24 ) 4,052 14.0 Intangible assets $ 80,243 $ (3,575 ) $ 76,668
Schedule of Estimated Future Amortization Expense for Intangible Asset	The estimated future amortization expense for intangible asset for the next five years and thereafter is as follows (in thousands): Year Ending December 31, 2021 $ 14,036 2022 13,666 2023 13,108 2024 10,316 2025 8,750 Thereafter 2,305 Total $ 62,181

Balance Sheet Components (Table

Balance Sheet Components (Tables)	12 Months Ended
	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Schedule of Accounts Receivable, Net	Accounts receivable, net consisted of the following (in thousands): As of December 31, 2020 2019 Gross accounts receivable $ 565,088 $ 360,194 Allowance for sales returns (5,912 ) (6,550 ) Allowance for sales incentives (30,838 ) (19,476 ) Allowance for doubtful accounts (4,181 ) (1,140 ) Other allowances (305 ) (355 ) Total allowances (41,236 ) (27,521 ) Total Accounts Receivable, net of allowances $ 523,852 $ 332,673
Schedule of Property and Equipment, Net	Property and equipment, net consisted of the following (in thousands): As of December 31, 2020 2019 Computers and equipment $ 30,859 $ 23,834 Leasehold improvements 144,013 93,239 Website and internal-use software 6,744 6,510 Office equipment and furniture 19,661 12,091 Total property and equipment 201,277 135,674 Accumulated depreciation and amortization (46,080 ) (32,412 ) Property and Equipment, net $ 155,197 $ 103,262
Schedule of Accrued Liabilities	Accrued liabilities consisted of the following (in thousands): As of December 31, 2020 2019 Payments due to content publishers $ 106,576 $ 57,376 Accrued cost of revenue 98,285 58,149 Marketing, retail and merchandising costs 43,645 7,624 Operating lease liability, current 35,647 17,896 Accrued royalty expense 15,713 18,040 Licensed content liability, current 6,165 1,679 Other accrued expenses 41,637 37,583 Total Accrued Liabilities $ 347,668 $ 198,347
Schedule of Deferred Revenue	Deferred revenue consisted of the following (in thousands): As of December 31, 2020 2019 Platform, current $ 27,587 $ 18,234 Player, current 27,878 21,627 Total deferred revenue, current 55,465 39,861 Platform, non-current 9,909 6,135 Player, non-current 11,374 9,235 Total deferred revenue, non-current 21,283 15,370 Total Deferred Revenue $ 76,748 $ 55,231

Licensed Content Assets (Tables

Licensed Content Assets (Tables)	12 Months Ended
	Dec. 31, 2020
Capitalized Licensed Content Costs [Abstract]
Schedule of Amortization Expense for Capitalized Licensed Content Assets	The following table reflects the amortization expense for the next three years for capitalized licensed content assets as of December 31, 2020 (in thousands): Year Ending December 31, 2021 $ 6,527 2022 1,338 2023 42

Fair Value Disclosure (Tables)

Fair Value Disclosure (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Schedule of Financial Assets Measured at Fair Value	The Company’s financial assets measured at fair value are as follows (in thousands): As of December 31, 2020 As of December 31, 2019 Fair Value Level 1 Fair Value Level 1 Assets: Cash and cash equivalents: Cash $ 1,021,022 $ 1,021,022 $ 463,820 $ 463,820 Money market funds 71,793 71,793 51,659 51,659 Restricted cash 434 434 1,854 1,854 Total assets measured and recorded at fair value $ 1,093,249 $ 1,093,249 $ 517,333 $ 517,333

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Schedule of Components of Lease Expense	The components of lease expense are as follows (in thousands): Years Ended December 31, 2020 2019 Operating lease cost (1) $ 56,348 $ 35,146 Sublease income (2,105 ) (2,622 ) Net operating lease cost $ 54,243 $ 32,524 (1) For the years ended December 31, 2020 and 2019, variable lease costs were $12.1 million and $4.9 million, respectively. Variable lease costs primarily include common area maintenance charges.
Schedule of Supplemental Cash Flow Information Related To Leases	Supplemental cash flow information related to leases is as follows (in thousands): Years Ended December 31, 2020 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash outflows from operating leases $ 30,664 $ 17,721 Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 12,031 $ 267,048
Schedule of Supplemental Balance Sheet Information Related to Leases	Supplemental balance sheet information related to leases was as follows (in thousands, except lease term and discount rate): As of December 31, 2020 2019 Operating lease right-of-use assets $ 266,197 $ 283,291 Included in accounts payable and accrued liabilities: Operating lease liability, current 35,647 17,896 Operating lease liability, non-current 307,936 301,694 Total operating lease liability $ 343,583 $ 319,590 Weighted Average Remaining Lease Term: Operating leases (in years) 9.05 9.98 Weighted Average Discount Rate: Operating leases 4.60 % 4.65 %
Schedule of Future Lease Payments under Operating Leases	Future lease payments under operating leases as of December 31, 2020 were as follows (in thousands): Year Ending December 31, Operating Leases 2021 $ 50,889 2022 47,377 2023 47,597 2024 46,635 2025 46,295 Thereafter 201,852 Total future lease payments 440,645 Less: imputed interest (81,076 ) Less: expected tenant improvement allowance (15,986 ) Total $ 343,583

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Schedule of Outstanding Debt	The Company’s outstanding debt as of December 31, 2020 and 2019 is as follows (in thousands): As of December 31, 2020 2019 Amount Effective Interest Rate Amount Effective Interest Rate Term Loan A Facility $ 95,000 2.03 % $ 100,000 3.48 % Less: Debt issuance costs (258 ) (392 ) Net carrying amount of debt $ 94,742 $ 99,608

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Schedule of Reserved Shares of Common Stock for Issuance	At December 31, 2020, the Company had reserved shares of common stock for issuance as follows (in thousands): As of December 31, 2020 Common stock awards granted under equity incentive plans 13,088 Common stock awards available for issuance under the 2017 Employee Stock Purchase Plan * 5,089 Common stock awards available for issuance under the 2017 Equity Incentive Plan 21,420 Total reserved shares of common stock 39,597
Summary of Restricted Stock Unit Activity	Restricted stock unit activity for the year ended December 31, 2020 is as follows (in thousands, except per share data): Number of Shares Weighted Average Grant Date Fair Value Per Share Balance, December 31, 2019 4,544 $ 67.30 Awarded 1,425 147.46 Released (1,253 ) 66.79 Forfeited (361 ) 76.55 Balance, December 31, 2020 - outstanding 4,355 $ 92.91
Schedule of Stock Option Activity	The following table summarizes the Company’s stock option activities under the 2008 Plan and 2017 Plan (in thousands, except per share data): Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Life (Years) Weighted Average Grant Date Fair Value Per Share Aggregate Intrinsic Value Balance, December 31, 2019 11,124 $ 14.84 6.2 — Granted 599 145.17 — $ 54.39 Exercised (2,854 ) 5.89 — — Forfeited and expired (136 ) 48.04 — — Balance, December 31, 2020 - outstanding 8,733 $ 26.19 5.7 — $ 2,670,743 Options exercisable at December 31, 2020 6,144 $ 8.00 4.8 — $ 1,990,694
Schedule of Share-based Compensation Expense	The following table shows total stock-based compensation expense for the years ended December 31, 2020, 2019 and 2018 (in thousands): Years Ended December 31, 2020 2019 2018 Cost of platform revenue $ 847 $ 342 $ 97 Cost of player revenue 1,407 1,072 469 Research and development 58,412 40,036 18,538 Sales and marketing 42,846 24,179 10,459 General and administrative 30,564 19,546 8,111 Total stock-based compensation $ 134,076 $ 85,175 $ 37,674
Summary of Assumptions Used to Value Stock Options Granted	The assumptions used to value stock options granted during the years ended December 31, 2020, 2019 and 2018 are as follows: Years Ended December 31, 2020 2019 2018 Expected term (in years) 5.0 - 6.7 5.0 - 6.7 5.3 - 6.8 Risk-free interest rate 0.22 - 1.67% 1.35 - 2.56% 2.32 - 2.88% Expected volatility 36 - 39% 35 - 36% 38 - 40% Dividend rate — — —

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Schedule of Components of Loss Before Income Taxes	The components of loss before income taxes consist of the following (in thousands): Years Ended December 31, 2020 2019 2018 United States $ (21,107 ) $ (63,453 ) $ (11,128 ) Foreign 2,655 2,534 1,795 Net loss before income taxes $ (18,452 ) $ (60,919 ) $ (9,333 )
Schedule of Income Tax (Benefit) Expense	The income tax (benefit) expense consisted of the following (in thousands): Years Ended December 31, 2020 2019 2018 Current: Federal $ (219 ) $ (47 ) $ — State 620 244 114 Foreign 743 108 184 1,144 305 298 Deferred: Foreign (2,089 ) (1,287 ) (774 ) Total $ (945 ) $ (982 ) $ (476 )
Schedule of Reconciliation of Statutory Federal Income Tax Rate to Effective Tax Rate	The following is a reconciliation of the statutory federal income tax rate to the Company’s effective tax rate: Years Ended December 31, 2020 2019 2018 U.S. federal income tax at statutory rate 21.0 % 21.0 % 21.0 % U.S. state and local income taxes (3.2 ) (0.4 ) (1.3 ) Change in valuation allowance (698.4 ) (213.4 ) (1,039.4 ) Federal research and development tax credit 102.9 30.8 166.2 Stock-based compensation 577.8 158.0 859.4 Meals and Entertainment (1.6 ) (1.4 ) (6.6 ) Permanent items — — (1.1 ) Foreign rate differential — (0.6 ) (1.5 ) Acquisition costs — (1.3 ) — Section 162(m) limitation (7.2 ) (1.4 ) — State apportionment change 4.4 1.3 — Tax rate change — (0.4 ) 2.4 Provision to return true-up 9.4 9.9 5.9 Other 0.1 (0.5 ) 0.1 Effective tax rate 5.2 % 1.6 % 5.1 %
Summary of Significant Components of Deferred Income Tax Assets and Liabilities	Significant components of the Company’s deferred income tax assets and liabilities consist of the following (in thousands): As of December 31, 2020 2019 Deferred tax assets: Net operating loss carryforwards $ 379,613 $ 263,512 Reserves and accruals 14,131 10,425 Research and development credits 104,110 73,442 Lease Obligation 91,373 81,639 Stock-based compensation 28,318 17,494 Total deferred tax assets 617,545 446,512 Deferred tax liabilities: Right-of-use asset (70,755 ) (72,243 ) Depreciation and amortization (11,707 ) (10,916 ) Total deferred tax liabilities (82,462 ) (83,159 ) Valuation allowance (530,887 ) (361,233 ) Net deferred tax assets $ 4,196 $ 2,120
Summary of Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands): As of December 31, 2020 2019 Unrecognized tax benefits at beginning of year $ 19,487 $ 14,541 Gross increase for tax positions of current year 9,959 10,378 Gross decrease due to statue expiration (75 ) (88 ) Gross decrease for tax positions of prior years (196 ) (5,344 ) Unrecognized tax benefits balance at end of year $ 29,175 $ 19,487

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2020
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 per share data): Years Ended December 31, 2020 2019 2018 Numerator: Net loss attributable to common stockholders $ (17,507 ) $ (59,937 ) $ (8,857 ) Denominator: Weighted-average shares used in computing net loss per share, basic and diluted 123,978 115,218 104,618 Net loss per share, basic and diluted $ (0.14 ) $ (0.52 ) $ (0.08 )
Schedule of Antidilutive Securities Excluded from Calculation of Diluted Net Loss Per Share	The potential common shares that were excluded from the calculation of diluted net loss per share because their effect would have been antidilutive for the periods presented are as follows (in thousands): Years Ended December 31, 2020 2019 2018 Equity awards to purchase common stock 13,088 15,668 20,057 Unvested shares of common stock issued upon early exercise of stock options and business acquisition 1 31 70 Total 13,089 15,699 20,127

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Schedule of Customer Accounting for 10% or More of Segment Revenue	Customers accounting for 10% or more of segment revenue, net, were as follows: Years Ended December 31, 2020 2019 2018 Platform segment revenue Customer H 13 % * * Player segment revenue Customer A 10 % 16 % 15 % Customer B 18 % 17 % 15 % Customer C 40 % 39 % 38 %

Quarterly Financial Data (Una_2

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Summary of the Company's Information on Total Revenue, Gross Profit, Net Income (Loss) and Earnings Per Share by Quarter	The following table summarizes the Company’s information on total revenue, gross profit, net income (loss) and earnings per share by quarter for the years ended December 31, 2020 and 2019. Three Months Ended Dec 31, 2020 Sep 30, 2020 Jun 30, 2020 Mar 31, 2020 Total Revenue $ 649,886 $ 451,663 $ 356,073 $ 320,766 Gross Profit 305,458 214,824 146,836 141,101 Net income (loss) attributable to common stockholders 67,306 12,947 (43,148 ) (54,612 ) Basic net income (loss) per share attributable to common stockholders 0.53 0.10 (0.35 ) (0.45 ) Diluted net income (loss) per share attributable to common stockholders 0.49 0.09 (0.35 ) (0.45 ) Three Months Ended Dec 31, 2019 Sep 30, 2019 Jun 30, 2019 Mar 31, 2019 Total Revenue $ 411,230 $ 260,928 $ 250,101 $ 206,662 Gross Profit 161,647 118,477 114,209 100,891 Net loss attributable to common stockholders (15,717 ) (25,155 ) (9,333 ) (9,732 ) Basic and diluted net loss per share attributable to common stockholders (0.13 ) (0.22 ) (0.08 ) (0.09 )

The Company - Additional Inform

The Company - Additional Information (Details)	12 Months Ended
	Dec. 31, 2020segment
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Conversion date	Feb. 1, 2008
Number of reportable segments operates	2

Significant Accounting Polici_4

Significant Accounting Policies and Basis of Presentation - Additional Information (Details)	12 Months Ended
	Dec. 31, 2020USD ($)FinancialInstitution	Dec. 31, 2019USD ($)FinancialInstitutionCustomer	Dec. 31, 2018USD ($)	Jan. 01, 2020USD ($)
Summary Of Significant Accounting Policies [Line Items]
Foreign currency gains (loss)	$ 1,300,000	$ (200,000)	$ (500,000)
Impairment of goodwill	0	0	0
Impairment of intangible assets	0	0
Impairment of capitalized licensed content assets	$ 0	0
Lessee, operating lease, existence of option to extend	true
Lessee, operating lease, existence of option to terminate	true
Advertising costs	$ 7,100,000	7,300,000	3,000,000
Cumulative-effect adjustment to accumulated deficit	$ 332,406,000	313,833,000
Change in accounting principle, accounting standards update, adopted [true false]	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2020
Change in accounting principle, accounting standards update, immaterial effect [true false]	true
Accounting Standards Update 2016-13
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted [true false]	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2020
Accounting Standards Update 2016-13 | Cumulative Effect, Period of Adoption, Adjustment | Revision of Prior Period, Adjustment
Summary Of Significant Accounting Policies [Line Items]
Cumulative-effect adjustment to accumulated deficit				$ 1,100,000
Accounting Standards Update 2019-02
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted [true false]	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2020
Change in accounting principle, accounting standards update, immaterial effect [true false]	true
Accounting Standards Update 2018-15
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted [true false]	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2020
Change in accounting principle, accounting standards update, immaterial effect [true false]	true
Accounting Standards Update 2018-13
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted [true false]	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2020
Change in accounting principle, accounting standards update, immaterial effect [true false]	true
Accounting Standards Update 2017-04
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted [true false]	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2020
Change in accounting principle, accounting standards update, immaterial effect [true false]	true
Accounting Standards Update 2019-04
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted [true false]	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2020
Change in accounting principle, accounting standards update, immaterial effect [true false]	true
Accounting Standards Update 2020-02
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted [true false]	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2020
Change in accounting principle, accounting standards update, immaterial effect [true false]	true
Accounting Standards Update 2020-03
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted [true false]	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2020
Change in accounting principle, accounting standards update, immaterial effect [true false]	true
Leasehold Improvements
Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives description	shorter of the lease term or their estimated useful lives, which range from five to ten years
Website and Internal-Use Software
Summary Of Significant Accounting Policies [Line Items]
Capitalized costs	$ 2,200,000	100,000	1,000,000
Amortized expenses	$ 500,000	$ 1,600,000	$ 2,000,000
Maximum
Summary Of Significant Accounting Policies [Line Items]
Business combination measurement period from acquisition	1 year
Property and equipment, estimated useful lives	5 years
Maximum | Leasehold Improvements
Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives	10 years
Maximum | Website and Internal-Use Software
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life	3 years
Minimum
Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives	18 months
Minimum | Leasehold Improvements
Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives	5 years
Minimum | Website and Internal-Use Software
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life	2 years
Customer Concentration Risk | Net Accounts Receivable
Summary Of Significant Accounting Policies [Line Items]
Number of customers accounted for 10% or more | Customer		0
Customer 1
Summary Of Significant Accounting Policies [Line Items]
Number of financial institutions which manage cash balances | FinancialInstitution	2	2
Customer 2
Summary Of Significant Accounting Policies [Line Items]
Number of financial institutions which manage cash balances | FinancialInstitution	2	2
Customer H | Customer Concentration Risk | Net Accounts Receivable
Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage	11.00%
Cash, Cash Equivalents and Short-term Investment | Customer 1
Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage	46.00%	65.00%
Cash, Cash Equivalents and Short-term Investment | Customer 2
Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage	26.00%	34.00%

Significant Accounting Polici_5

Significant Accounting Policies and Basis of Presentation - Schedule of Allowance for Sales Returns (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	$ (27,521)
Ending balance	(41,236)	$ (27,521)
Allowance for Sales Returns
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	(6,550)	(7,335)	$ (6,907)
Charged to revenue	(14,594)	(15,541)	(17,396)
Utilization of sales return reserve	15,232	16,326	16,968
Ending balance	$ (5,912)	$ (6,550)	$ (7,335)

Significant Accounting Polici_6

Significant Accounting Policies and Basis of Presentation - Schedule of Allowance for Sales Incentives (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	$ (27,521)
Ending balance	(41,236)	$ (27,521)
Allowance for Sales Incentives
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	(19,476)	(13,750)	$ (10,442)
Charged to revenue	(68,315)	(65,676)	(50,958)
Utilization of sales incentive reserve	56,953	59,950	47,650
Ending balance	$ (30,838)	$ (19,476)	$ (13,750)

Significant Accounting Polici_7

Significant Accounting Policies and Basis of Presentation - Schedule of Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	$ (27,521)
Ending balance	(41,236)	$ (27,521)
Allowance for Doubtful Accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	(1,140)	(686)	$ (63)
Adjusted balance, beginning of period	(2,206)	(686)	(63)
Charged to revenue	(3,801)	(704)	(876)
Adjustments for recovery and write-off	1,826	250	253
Ending balance	(4,181)	$ (1,140)	$ (686)
Allowance for Doubtful Accounts | Accounting Standards Update 2016-13
Movement in Valuation Allowances and Reserves [Roll Forward]
Impact of adoption of ASU 2016-13	$ (1,066)

Revenue - Additional Informatio

Revenue - Additional Information (Details) $ in Millions	Nov. 30, 2019USD ($)	Dec. 31, 2020USD ($)segment	Dec. 31, 2019USD ($)	Dec. 31, 2018
Disaggregation Of Revenue [Line Items]
Number of reportable segment | segment		2
Contract with customer assets increase (decrease)		$ 3.8	$ 2.8
Increase (decrease) in deferred revenue		21.5	(9.8)
Increase (decrease) in deferred revenue due to change in timing of fulfillment of performance obligations		12.4
Increase (decrease) in deferred revenue recognized related to unspecified upgrades		8.4
Deferred revenue increase decrease due to revenue recognized upon customer acceptance			5
Deferred revenue recognized		42.9	$ 52.5
Estimated contracted revenue		$ 513.7
Revenue, remaining performance obligation, expected timing of satisfaction, Description		Revenue allocated to remaining performance obligations represents estimated contracted revenue that has not yet been recognized which includes unearned revenue and amounts that will be invoiced and recognized as revenue in future periods. Estimated contracted revenue was $513.7 million as of December 31, 2020 of which the Company expects to recognize approximately 55% over the next 12 months and the remainder thereafter.
Revenue remaining performance obligation percentage of revenue expected to be recognized		55.00%
Revenue recognized from performance obligation satisfied in previous period	$ 10.9	$ 14.4
Customer Concentration Risk | Net Revenue | Customer C
Disaggregation Of Revenue [Line Items]
Concentration risk		12.00%	14.00%	18.00%

Revenue - Schedule of Contract

Revenue - Schedule of Contract Balances (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Schedule Of Contract Balances [Line Items]
Accounts receivable, net	$ 523,852	$ 332,673	$ 183,078
Deferred revenue, current portion	55,465	39,861	45,442
Deferred revenue, non-current portion	21,283	15,370	19,594
Total deferred revenue	76,748	55,231	65,036
Prepaid Expenses and Other Current Assets
Schedule Of Contract Balances [Line Items]
Contract assets (included in Prepaid expenses and other current assets)	$ 7,431	$ 3,588	$ 753

Business Combination - Addition

Business Combination - Additional Information (Details) - Boston-based Dataxu, Inc, Demand-Side Platform (DSP) - USD ($) shares in Thousands, $ in Millions	Nov. 08, 2019	Dec. 31, 2020
Business Acquisition [Line Items]
Business combination, date of merger agreement	Oct. 22, 2019
Purchase consideration	$ 147.3
Business combination, aggregate cash consideration	77.6
Business combination, aggregate fair value	69.7
Escrow deposit related to acquisition	$ 18.8
Escrow deposit unreleased related to acquisition		$ 13.6
Class A Common Stock
Business Acquisition [Line Items]
Shares of common stock issued	571,459

Business Combination - Schedule

Business Combination - Schedule of Allocation of Purchase Consideration to Tangible and Intangible Assets Acquired and Liabilities Assumed on Acquisition Date (Details) - USD ($) $ in Thousands	Nov. 08, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Assets acquired
Goodwill		$ 73,058	$ 74,116	$ 1,382
Boston-based Dataxu, Inc, Demand-Side Platform (DSP)
Assets acquired
Current assets	$ 50,829
Restricted cash	1,303
Property and equipment, net	4,503
Goodwill	71,676
Operating lease right-of-use assets	24,658
Other long-term assets	235
Total assets acquired	223,404
Liabilities assumed
Current liabilities	(51,428)
Operating lease liabilities	(24,658)
Total liabilities assumed	(76,086)
Total purchase consideration	147,318
Boston-based Dataxu, Inc, Demand-Side Platform (DSP) | Developed Technology
Assets acquired
Intangible assets	$ 56,400
Liabilities assumed
Estimated Useful Lives (in years)	6 years
Boston-based Dataxu, Inc, Demand-Side Platform (DSP) | Customer Relationships
Assets acquired
Intangible assets	$ 13,400
Liabilities assumed
Estimated Useful Lives (in years)	4 years
Boston-based Dataxu, Inc, Demand-Side Platform (DSP) | Tradename
Assets acquired
Intangible assets	$ 400
Liabilities assumed
Estimated Useful Lives (in years)	6 months

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Schedule of Carrying Value of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Goodwill [Line Items]
Beginning Balance	$ 74,116	$ 1,382
Ending Balance	73,058	74,116
Boston-based Dataxu, Inc, Demand-Side Platform (DSP)
Goodwill [Line Items]
Addition		$ 72,734
Adjustment: dataxu working capital adjustments	$ (1,058)

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill impairment loss	$ 0	$ 0	$ 0
Amortization of intangible assets	$ 14,500,000	$ 2,800,000	$ 600,000

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Summary of Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 80,243	$ 80,243
Accumulated Amortization	(18,062)	(3,575)
Net Carrying Amount	62,181	76,668
Developed Technology
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	62,367	62,367
Accumulated Amortization	(13,439)	(2,860)
Net Carrying Amount	$ 48,928	$ 59,507
Weighted-Average Useful Lives (in years)	5 years 10 months 24 days	5 years 10 months 24 days
Customer Relationships
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 13,400	$ 13,400
Accumulated Amortization	(3,908)	(558)
Net Carrying Amount	$ 9,492	$ 12,842
Weighted-Average Useful Lives (in years)	4 years	4 years
Tradename
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 400	$ 400
Accumulated Amortization	$ (400)	(133)
Net Carrying Amount		$ 267
Weighted-Average Useful Lives (in years)	6 months	6 months
Patents
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 4,076	$ 4,076
Accumulated Amortization	(315)	(24)
Net Carrying Amount	$ 3,761	$ 4,052
Weighted-Average Useful Lives (in years)	14 years	14 years

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets - Schedule of Estimated Future Amortization Expense for Intangible Asset (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
2021	$ 14,036
2022	13,666
2023	13,108
2024	10,316
2025	8,750
Thereafter	2,305
Net Carrying Amount	$ 62,181	$ 76,668

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Accounts Receivable, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Valuation And Qualifying Accounts Disclosure [Line Items]
Gross accounts receivable	$ 565,088	$ 360,194
Allowance for accounts receivable	(41,236)	(27,521)
Total Accounts Receivable, net of allowances	523,852	332,673
Allowance for Sales Returns
Valuation And Qualifying Accounts Disclosure [Line Items]
Allowance for accounts receivable	(5,912)	(6,550)	$ (7,335)	$ (6,907)
Allowance for Sales Incentives
Valuation And Qualifying Accounts Disclosure [Line Items]
Allowance for accounts receivable	(30,838)	(19,476)	(13,750)	(10,442)
Allowance for Doubtful Accounts
Valuation And Qualifying Accounts Disclosure [Line Items]
Allowance for accounts receivable	(4,181)	(1,140)	$ (686)	$ (63)
Other Allowances
Valuation And Qualifying Accounts Disclosure [Line Items]
Allowance for accounts receivable	$ (305)	$ (355)

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Total property and equipment	$ 201,277	$ 135,674
Accumulated depreciation and amortization	(46,080)	(32,412)
Property and Equipment, net	155,197	103,262
Computer and Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	30,859	23,834
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment	144,013	93,239
Website and Internal-Use Software
Property Plant And Equipment [Line Items]
Total property and equipment	6,744	6,510
Office Equipment and Furniture
Property Plant And Equipment [Line Items]
Total property and equipment	$ 19,661	$ 12,091

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Balance Sheet Related Disclosures [Abstract]
Depreciation and amortization	$ 21.7	$ 12.8	$ 7.8

Balance Sheet Components - Sc_3

Balance Sheet Components - Schedule of Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accrued Liabilities Current [Abstract]
Payments due to content publishers	$ 106,576	$ 57,376
Accrued cost of revenue	98,285	58,149
Marketing, retail and merchandising costs	43,645	7,624
Operating lease liability, current	35,647	17,896
Accrued royalty expense	15,713	18,040
Licensed content liability, current	6,165	1,679
Other accrued expenses	41,637	37,583
Total Accrued Liabilities	$ 347,668	$ 198,347

Balance Sheet Components - Sc_4

Balance Sheet Components - Schedule of Deferred Revenue (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Deferred Revenue Arrangement [Line Items]
Total deferred revenue, current	$ 55,465	$ 39,861	$ 45,442
Total deferred revenue, non-current	21,283	15,370	19,594
Total deferred revenue	76,748	55,231	$ 65,036
Platform
Deferred Revenue Arrangement [Line Items]
Total deferred revenue, current	27,587	18,234
Total deferred revenue, non-current	9,909	6,135
Player
Deferred Revenue Arrangement [Line Items]
Total deferred revenue, current	27,878	21,627
Total deferred revenue, non-current	$ 11,374	$ 9,235

Licensed Content Assets - Addit

Licensed Content Assets - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Licensed Content Assets [Line Items]
Change in accounting principle, accounting standards update, adopted [true false]	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2020
Change in accounting principle, accounting standards update, immaterial effect [true false]	true
Accounting Standards Update Extensible List	us-gaap:AccountingStandardsUpdate201902Member
Licensed content expenses	$ 7,900,000	$ 1,700,000
Amortization of content assets	22,392,000	2,914,000
Impairment of capitalized licensed content assets	0	$ 0
Licensed Content Assets
Licensed Content Assets [Line Items]
Impairment of capitalized licensed content assets	$ 0

Licensed Content Assets - Sched

Licensed Content Assets - Schedule of Amortization Expense for Licensed Content Assets (Details) $ in Thousands	Dec. 31, 2020USD ($)
Capitalized Licensed Content Costs [Abstract]
2021	$ 6,527
2022	1,338
2023	$ 42

Fair Value Disclosure - Schedul

Fair Value Disclosure - Schedule of Financial Assets Measured at Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Assets:
Restricted cash	$ 434	$ 1,854
Total assets measured and recorded at fair value	1,093,249	517,333
Level 1
Assets:
Restricted cash		1,854
Total assets measured and recorded at fair value		517,333
Cash
Assets:
Cash and cash equivalents	1,021,022	463,820
Cash | Level 1
Assets:
Cash and cash equivalents		463,820
Money Market Fund
Assets:
Cash and cash equivalents	$ 71,793	51,659
Money Market Fund | Level 1
Assets:
Cash and cash equivalents		$ 51,659

Fair Value Disclosure - Additio

Fair Value Disclosure - Additional Information (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Money Market Fund | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	$ 71.8	$ 51.7

Leases - Additional Information

Leases - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)
Leases [Line Items]
Lessee, operating lease, existence of option to extend	true
Lessee, operating lease, existence of option to terminate	true
Commitment relating to operating lease, that have not yet commenced	$ 2.7
Operating leases that have not yet commenced, lease terms	2 years
Minimum
Leases [Line Items]
Remaining lease term, operating lease	1 year
Maximum
Leases [Line Items]
Remaining lease term, operating lease	10 years

Leases - Schedule of Components

Leases - Schedule of Components of Lease Expense (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease cost	[1]	$ 56,348	$ 35,146
Sublease income		(2,105)	(2,622)
Net operating lease cost		$ 54,243	$ 32,524
[1]	For the years ended December 31, 2020 and 2019, variable lease costs were $12.1 million and $4.9 million, respectively. Variable lease costs primarily include common area maintenance charges.

Leases - Schedule of Componen_2

Leases - Schedule of Components of Lease Expense (Parenthetical) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Variable lease costs	$ 12.1	$ 4.9

Leases - Schedule of Supplement

Leases - Schedule of Supplemental Cash Flow Information Related to Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash outflows from operating leases	$ 30,664	$ 17,721
Right-of-use assets obtained in exchange for lease obligations:
Operating leases	$ 12,031	$ 267,048

Leases - Schedule of Suppleme_2

Leases - Schedule of Supplemental Balance Sheet Information Related to Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease right-of-use assets	$ 266,197	$ 283,291
Operating lease liability, current	$ 35,647	$ 17,896
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:AccruedLiabilitiesCurrent	us-gaap:AccruedLiabilitiesCurrent
Operating lease liability, non-current	$ 307,936	$ 301,694
Total operating lease liability	$ 343,583	$ 319,590
Weighted Average Remaining Lease Term:
Operating leases (in years)	9 years 18 days	9 years 11 months 23 days
Weighted Average Discount Rate:
Operating leases	4.60%	4.65%

Leases - Schedule of Future Lea

Leases - Schedule of Future Lease Payments under Operating Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
2021	$ 50,889
2022	47,377
2023	47,597
2024	46,635
2025	46,295
Thereafter	201,852
Total future lease payments	440,645
Less: imputed interest	(81,076)
Less: expected tenant improvement allowance	(15,986)
Total	$ 343,583	$ 319,590

Debt - Schedule of Outstanding

Debt - Schedule of Outstanding Debt (Details) - Term Loan A Facility - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Principal amount	$ 95,000	$ 100,000
Less: Debt issuance costs	(258)	(392)
Net carrying amount of debt	$ 94,742	$ 99,608
Effective Interest Rate	2.03%	3.48%

Debt - Additional Information (

Debt - Additional Information (Details) - USD ($)	Nov. 18, 2019	May 03, 2019	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Letters of credit outstanding				$ 30,900,000	$ 31,800,000
Credit Agreement
Debt Instrument [Line Items]
Interest expense				2,600,000	400,000
Credit Agreement | Morgan Stanley Senior Funding, Inc | Minimum
Debt Instrument [Line Items]
Adjusted quick ratio		1.00%
Credit Agreement | Morgan Stanley Senior Funding, Inc | Revolving Credit Facility
Debt Instrument [Line Items]
Debt instrument term, years		4 years
Maximum borrowing capacity		$ 100,000,000
Amount borrowed under debt facility			$ 69,300,000
Credit facility expiration and maturity month and year		2023-02
Letters of credit outstanding				$ 30,800,000	$ 30,700,000
Credit Agreement | Morgan Stanley Senior Funding, Inc | Revolving Credit Facility | Adjusted One-Month LIBOR
Debt Instrument [Line Items]
Debt instrument, applicable margin on variable rate			1.75%
Credit Agreement | Morgan Stanley Senior Funding, Inc | Term Loan A Facility
Debt Instrument [Line Items]
Debt instrument term, years		4 years
Maximum borrowing capacity		$ 100,000,000
Amount borrowed under debt facility	$ 100,000,000
Debt instrument, amortization description				Loans under the Term Loan A Facility amortize in equal quarterly installments beginning on March 31, 2020, in an aggregate annual amount equal to (i) on or prior to December 31, 2021, 1.25% of the drawn principal amount of the Term Loan Facility or $1.25 million and (ii) thereafter, 2.50% of the drawn principal amount of the Term Loan Facility or $2.5 million, with the remaining balance payable on the maturity date of the Term Loan A Facility in February 2023.
Debt instrument maturity month and year		2023-02
Credit Agreement | Morgan Stanley Senior Funding, Inc | Term Loan A Facility | On or Prior to December 31, 2021
Debt Instrument [Line Items]
Percentage of amortization on drawn principal amount		1.25%
Amortization, aggregate principal amount		$ 1,250,000
Credit Agreement | Morgan Stanley Senior Funding, Inc | Term Loan A Facility | Thereafter December 31, 2021
Debt Instrument [Line Items]
Percentage of amortization on drawn principal amount		2.50%
Amortization, aggregate principal amount		$ 2,500,000
Credit Agreement | Morgan Stanley Senior Funding, Inc | Term Loan A Facility | Adjusted One-Month LIBOR
Debt Instrument [Line Items]
Debt instrument, applicable margin on variable rate	1.75%
Credit Agreement | Morgan Stanley Senior Funding, Inc | Uncommitted Incremental Facility
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 50,000,000
Debt to company's EBITDA, description				1.0x of the Company’s EBITDA for the most recently completed four fiscal quarter period
Credit Agreement | Morgan Stanley Senior Funding, Inc | Uncommitted Incremental Facility | Maximum
Debt Instrument [Line Items]
Secured leverage ratio		1.50%

Stockholders' Equity - Preferre

Stockholders' Equity - Preferred Stock - Additional Information (Details) - shares	Dec. 31, 2020	Dec. 31, 2019
Equity [Abstract]
Preferred stock, shares authorized	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0

Stockholders' Equity - Common S

Stockholders' Equity - Common Stock - Additional Information (Details)	12 Months Ended
	Dec. 31, 2020Class
Class Of Stock [Line Items]
Number of classes	2
Class A Common Stock
Class Of Stock [Line Items]
Common stock, voting right	one vote for each share
Class B Common Stock
Class Of Stock [Line Items]
Common stock, voting right	ten votes for each share

Stockholders' Equity - At-the-M

Stockholders' Equity - At-the-Market Offering - Additional Information (Details) - At-the-Market Offerings - Class A Common Stock $ / shares in Units, shares in Millions, $ in Millions	May 13, 2020USD ($)$ / sharesshares
Class Of Stock [Line Items]
Aggregate shares of common stock, sold | shares	4
Gross proceeds from issuance of common stock	$ 504
Average selling price per share | $ / shares	$ 126.01
Stock Issuance Costs	$ 6.8

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Reserved Shares of Common Stock for Issuance (Details) shares in Thousands	Dec. 31, 2020shares
Class Of Stock [Line Items]
Total reserved shares of common stock	39,597
Equity Incentive Plan
Class Of Stock [Line Items]
Common stock awards granted under equity incentive plans	13,088
2017 Employee Stock Purchase Plan
Class Of Stock [Line Items]
Common stock awards available for issuance	5,089	[1]
2017 Plan
Class Of Stock [Line Items]
Common stock awards available for issuance	21,420
[1]	The Company has not issued any common stock pursuant to the 2017 Employee Stock Purchase Plan.

Stockholders' Equity - Equity I

Stockholders' Equity - Equity Incentive Plans - Additional Information (Details)	12 Months Ended
	Dec. 31, 2020Plan
Class Of Stock [Line Items]
Number of equity incentive plans	2
2008 Plan and 2017 Plan | Employee Stock Option
Class Of Stock [Line Items]
Percentage of voting rights	10.00%
2008 Plan and 2017 Plan | Employee Stock Option | Minimum | 10% Shareholder
Class Of Stock [Line Items]
Stock option fair market value at the date of grant, percent	110.00%

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Restricted Stock Unit Activity (Details) - Restricted Stock Units shares in Thousands	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Beginning balance Number of Shares, outstanding | shares	4,544
Number of Shares, Awarded | shares	1,425
Number of Shares, Released | shares	(1,253)
Number of Shares, Forfeited | shares	(361)
Ending balance, Number of Shares outstanding | shares	4,355
Weighted Average Grant Date Fair Value Per Share, Beginning balance | $ / shares	$ 67.30
Weighted Average Grant Date Fair Value Per Share, Awarded | $ / shares	147.46
Weighted Average Grant Date Fair Value Per Share, Released | $ / shares	66.79
Weighted Average Grant Date Fair Value Per Share, Forfeited | $ / shares	76.55
Weighted Average Grant Date Fair Value Per Share, Ending balance | $ / shares	$ 92.91

Stockholders' Equity - Restrict

Stockholders' Equity - Restricted Stock Units - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Expected weighted average period to recognize unrecognized stock compensation expense	1 year 9 months 10 days
Restricted Stock Units
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Grant-date fair value of restricted stock units granted	$ 210.1	$ 195.2	$ 184.7
Fair value of restricted stock units vested	83.7	$ 40.5	$ 11.4
Unrecognized stock compensation expense	$ 336.4
Expected weighted average period to recognize unrecognized stock compensation expense	2 years 3 months 3 days

Stockholders' Equity - Summar_2

Stockholders' Equity - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Granted, Weighted Average Grant Date Fair Value Per Share	$ 54.39	$ 39.23	$ 22.96
2008 Plan and 2017 Plan
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance, Number of Shares	11,124
Granted, Number of Shares	599
Exercised, Number of Shares	(2,854)
Forfeited and expired, Number of Shares	(136)
Balance, Number of Shares	8,733	11,124
Options exercisable at December 31, 2020, Number of Shares	6,144
Balance, Weighted Average Exercise Price	$ 14.84
Granted, Weighted Average Exercise Price	145.17
Exercised, Weighted Average Exercise Price	5.89
Forfeited and expired, Weighted Average Exercise Price	48.04
Balance, Weighted Average Exercise Price	26.19	$ 14.84
Options exercisable at December 31, 2020, Weighted Average Exercise Price	$ 8
Balance, Weighted Average Remaining Contractual Life (Years)	5 years 8 months 12 days	6 years 2 months 12 days
Options exercisable at December 31, 2020, Weighted Average Remaining Contractual Life (Years)	4 years 9 months 18 days
Granted, Weighted Average Grant Date Fair Value Per Share	$ 54.39
Outstanding, ending balance	$ 2,670,743
Options exercisable, ending balance	$ 1,990,694

Stockholders' Equity - Stock Op

Stockholders' Equity - Stock Option Plan - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Weighted average grant-date fair value of stock options granted	$ 54.39	$ 39.23	$ 22.96
Intrinsic value of stock options exercised	$ 470.8	$ 474.2	$ 445.9
Unrecognized stock compensation expense	$ 50.8
Expected weighted average period to recognize unrecognized stock compensation expense	1 year 9 months 10 days

Stockholders' Equity - Stock-ba

Stockholders' Equity - Stock-based Compensation - Additional Information (Details)	12 Months Ended
	Dec. 31, 2020
Class Of Stock [Line Items]
Stock option term	10 years
Employee Stock Option | Tranche One
Class Of Stock [Line Items]
Stock granted to employees vesting rights, percentage	25.00%
Employee Stock Option | Tranche Two
Class Of Stock [Line Items]
Stock granted to employees vesting rights, terms of award	one year and then 1/48th monthly thereafter
Restricted Stock Units
Class Of Stock [Line Items]
Share-based compensation arrangement by share-based payment vesting period	4 years

Stockholders' Equity - Schedu_2

Stockholders' Equity - Schedule of Share-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 134,076	$ 85,175	$ 37,674
Cost of Revenue | Platform
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	847	342	97
Cost of Revenue | Player
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	1,407	1,072	469
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	58,412	40,036	18,538
Sales and Marketing
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	42,846	24,179	10,459
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 30,564	$ 19,546	$ 8,111

Stockholders' Equity - Expected

Stockholders' Equity - Expected Dividends - Additional Information (Details)	12 Months Ended
	Dec. 31, 2020USD ($)
Equity [Abstract]
Expected dividend	$ 0

Stockholders' Equity - Summar_3

Stockholders' Equity - Summary of Assumptions Used to Value Stock Options Granted (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate, Minimum	0.22%	1.35%	2.32%
Risk-free interest rate, Maximum	1.67%	2.56%	2.88%
Expected volatility, Minimum	36.00%	35.00%	38.00%
Expected volatility, Maximum	39.00%	36.00%	40.00%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	5 years	5 years	5 years 3 months 18 days
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 years 8 months 12 days	6 years 8 months 12 days	6 years 9 months 18 days

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Commitments And Contingencies [Line Items]
Letters of credit outstanding	$ 30.9	$ 31.8
Letters of credit expiration date	Dec. 31, 2030
Player | Cost of Revenue
Commitments And Contingencies [Line Items]
Expense related to patent infringements		9.9
Reversal of revenue contingencies accrual		8.9
Intellectual Property Licensing
Commitments And Contingencies [Line Items]
Loss contingencies accrual, change in estimated liabilities		8.9
Manufacturing
Commitments And Contingencies [Line Items]
Purchase commitments for inventory and license	$ 185.9
Manufacturing | Accrued Liabilities
Commitments And Contingencies [Line Items]
Loss on purchase obligation for inventory	1.2	0.3
License Content | Accrued Liabilities
Commitments And Contingencies [Line Items]
Purchase commitments for inventory and license	6.2	$ 1.7
License Content | Other Long-Term Liabilities
Commitments And Contingencies [Line Items]
Purchase commitments for inventory and license	1.4
Content Publishers
Commitments And Contingencies [Line Items]
Purchase commitments for inventory and license	$ 71

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Components of Loss Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
United States	$ (21,107)	$ (63,453)	$ (11,128)
Foreign	2,655	2,534	1,795
Loss Before Income Taxes	$ (18,452)	$ (60,919)	$ (9,333)

Income Taxes - Schedule of Inco

Income Taxes - Schedule of Income Tax (Benefit) Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current:
Federal	$ (219)	$ (47)
State	620	244	$ 114
Foreign	743	108	184
Current income tax expense	1,144	305	298
Deferred:
Foreign	(2,089)	(1,287)	(774)
Total	$ (945)	$ (982)	$ (476)

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliation of Statutory Federal Income Tax Rate to Effective Tax Rate (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
U.S. federal income tax at statutory rate	21.00%	21.00%	21.00%
U.S. state and local income taxes	(3.20%)	(0.40%)	(1.30%)
Change in valuation allowance	(698.40%)	(213.40%)	(1039.40%)
Federal research and development tax credit	102.90%	30.80%	166.20%
Stock-based compensation	577.80%	158.00%	859.40%
Meals and Entertainment	(1.60%)	(1.40%)	(6.60%)
Permanent items			(1.10%)
Foreign rate differential		(0.60%)	(1.50%)
Acquisition costs		(1.30%)
Section 162(m) limitation	(7.20%)	(1.40%)
State apportionment change	4.40%	1.30%
Tax rate change		(0.40%)	2.40%
Provision to return true-up	9.40%	9.90%	5.90%
Other	0.10%	(0.50%)	0.10%
Effective tax rate	5.20%	1.60%	5.10%

Income Taxes - Summary of Signi

Income Taxes - Summary of Significant Components of Deferred Income Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Net operating loss carryforwards	$ 379,613	$ 263,512
Reserves and accruals	14,131	10,425
Research and development credits	104,110	73,442
Lease Obligation	91,373	81,639
Stock-based compensation	28,318	17,494
Total deferred tax assets	617,545	446,512
Deferred tax liabilities:
Right-of-use asset	(70,755)	(72,243)
Depreciation and amortization	(11,707)	(10,916)
Total deferred tax liabilities	(82,462)	(83,159)
Valuation allowance	(530,887)	(361,233)
Net deferred tax assets	$ 4,196	$ 2,120

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)Ownership	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Income Taxes Disclosure [Line Items]
Increased in valuation allowance	$ 169,700	$ 178,900
Research and development tax credit carryforwards	104,110	73,442
Unrecognized tax benefits	29,175	$ 19,487	$ 14,541
Accrued interest and penalties	$ 200
Income tax examination description	The Company is currently under examination by Texas Comptroller for calendar tax years 2015, 2016, and 2017. All tax years remain subject to examination by federal and state authorities. These audits include questioning the timing and amount of deductions; the nexus of income among various tax jurisdictions; and compliance with federal, state, and local tax laws.
Research and Development Credits
Income Taxes Disclosure [Line Items]
Unrecognized tax benefits	$ 28,300
Federal
Income Taxes Disclosure [Line Items]
Net operating loss carryforwards	$ 1,423,100
Net operating loss carryforwards, expiration beginning year	2028
Research and development tax credit carryforwards	$ 82,600
Tax credit carryforwards, expiration beginning year	2028
State
Income Taxes Disclosure [Line Items]
Net operating loss carryforwards	$ 1,273,900
Net operating loss carryforwards, expiration year	2020
Research and development tax credit carryforwards	$ 59,400
Tax credit carryforwards, expiration beginning year	2035
UK
Income Taxes Disclosure [Line Items]
Net operating loss carryforwards	$ 17,600
Research and development tax credit carryforwards	300
Denmark
Income Taxes Disclosure [Line Items]
Net operating loss carryforwards	$ 800
Section 382
Income Taxes Disclosure [Line Items]
Number of ownership changes for income tax purposes | Ownership	4
International
Income Taxes Disclosure [Line Items]
Unrecognized tax benefits	$ 900

Income Taxes - Summary of Recon

Income Taxes - Summary of Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Unrecognized tax benefits at beginning of year	$ 19,487	$ 14,541
Gross increase for tax positions of current year	9,959	10,378
Gross decrease due to statue expiration	(75)	(88)
Gross decrease for tax positions of prior years	(196)	(5,344)
Unrecognized tax benefits balance at end of year	$ 29,175	$ 19,487

Related-Party Transactions - Ad

Related-Party Transactions - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2020
Related Party Transaction [Line Items]
Payable to or receivable from related parties			$ 0
CEO Holds Majority Voting Interest
Related Party Transaction [Line Items]
Related party transaction expense	$ 1,200,000	$ 0
Payable/ outstanding to related parties	0
Strategic Investors
Related Party Transaction [Line Items]
Revenue from related parties	8,500,000	4,100,000
Receivable from related parties	2,400,000
Related party transaction expense	1,300,000	$ 1,300,000
Payable/ outstanding to related parties	$ 400,000

Retirement Plans - Additional I

Retirement Plans - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Contribution Plan Disclosure [Line Items]
Employer contribution amount to plan	$ 700,000	$ 500,000	$ 400,000
Savings Plan
Defined Contribution Plan Disclosure [Line Items]
Employer contribution amount to plan	$ 0	$ 0	$ 0

Net Loss Per Share - Summary of

Net Loss Per Share - Summary of Calculation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Numerator:
Net Loss Attributable to Common Stockholders	$ 67,306	$ 12,947	$ (43,148)	$ (54,612)	$ (15,717)	$ (25,155)	$ (9,333)	$ (9,732)	$ (17,507)	$ (59,937)	$ (8,857)
Denominator:
Weighted-average shares used in computing net loss per share, basic and diluted									123,978	115,218	104,618
Net loss per share, basic and diluted					$ (0.13)	$ (0.22)	$ (0.08)	$ (0.09)	$ (0.14)	$ (0.52)	$ (0.08)

Net Loss Per Share - Schedule o

Net Loss Per Share - Schedule of Antidilutive Securities Excluded from Calculation of Diluted Net Loss Per Share (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted net loss per share	13,089	15,699	20,127
Equity Awards to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted net loss per share	13,088	15,668	20,057
Unvested Shares of Common Stock Issued Upon Early Exercise of Stock Options and Business Acquisition
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted net loss per share	1	31	70

Segment Information - Additiona

Segment Information - Additional Information (Details) - segment	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Number of reportable segments	2
Net Revenue | Geographic Concentration Risk | International Market | Maximum
Segment Reporting Information [Line Items]
Concentration risk	10.00%	10.00%

Segment Information - Schedule

Segment Information - Schedule of Customer Accounting for 10% or More of Segment Revenue (Details) - Net Revenue - Customer Concentration Risk	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Customer C
Entity Wide Revenue Major Customer [Line Items]
Concentration risk	12.00%	14.00%	18.00%
Platform | Customer H
Entity Wide Revenue Major Customer [Line Items]
Concentration risk	13.00%
Player | Customer A
Entity Wide Revenue Major Customer [Line Items]
Concentration risk	10.00%	16.00%	15.00%
Player | Customer B
Entity Wide Revenue Major Customer [Line Items]
Concentration risk	18.00%	17.00%	15.00%
Player | Customer C
Entity Wide Revenue Major Customer [Line Items]
Concentration risk	40.00%	39.00%	38.00%

Quarterly Financial Data (Una_3

Quarterly Financial Data (Unaudited) - Summary of the Company's Information on Total Revenue, Gross Profit, Net Income (Loss) and Earnings Per Share by Quarter (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Total Revenue	$ 649,886	$ 451,663	$ 356,073	$ 320,766	$ 411,230	$ 260,928	$ 250,101	$ 206,662	$ 1,778,388	$ 1,128,921	$ 742,506
Gross Profit	305,458	214,824	146,836	141,101	161,647	118,477	114,209	100,891	808,219	495,224	332,148
Net income (loss) attributable to common stockholders	$ 67,306	$ 12,947	$ (43,148)	$ (54,612)	$ (15,717)	$ (25,155)	$ (9,333)	$ (9,732)	$ (17,507)	$ (59,937)	$ (8,857)
Basic net income (loss) per share attributable to common stockholders	$ 0.53	$ 0.10	$ (0.35)	$ (0.45)
Diluted net income (loss) per share attributable to common stockholders	$ 0.49	$ 0.09	$ (0.35)	$ (0.45)
Basic and diluted net loss per share attributable to common stockholders					$ (0.13)	$ (0.22)	$ (0.08)	$ (0.09)	$ (0.14)	$ (0.52)	$ (0.08)