3.20.4 html 275 522 1 true 97 0 false 10 false false R1.htm 100000 - Document - Document and Entity Information Sheet http://www.roku.com/20201231/taxonomy/role/DocumentDocumentAndEntityInformation Document and Entity Information Cover 1 false false R2.htm 100010 - Statement - Consolidated Balance Sheets Sheet http://www.roku.com/20201231/taxonomy/role/StatementConsolidatedBalanceSheets Consolidated Balance Sheets Statements 2 false false R3.htm 100020 - Statement - Consolidated Balance Sheets (Parenthetical) Sheet http://www.roku.com/20201231/taxonomy/role/StatementConsolidatedBalanceSheetsParenthetical Consolidated Balance Sheets (Parenthetical) Statements 3 false false R4.htm 100030 - Statement - Consolidated Statements of Operations Sheet http://www.roku.com/20201231/taxonomy/role/StatementConsolidatedStatementsOfOperations Consolidated Statements of Operations Statements 4 false false R5.htm 100040 - Statement - Consolidated Statements of Comprehensive Loss Sheet http://www.roku.com/20201231/taxonomy/role/StatementConsolidatedStatementsOfComprehensiveLoss Consolidated Statements of Comprehensive Loss Statements 5 false false R6.htm 100050 - Statement - Consolidated Statements of Stockholders' Equity Sheet http://www.roku.com/20201231/taxonomy/role/StatementConsolidatedStatementsOfStockholdersEquity Consolidated Statements of Stockholders' Equity Statements 6 false false R7.htm 100060 - Statement - Consolidated Statements of Stockholders' Equity (Parenthetical) Sheet http://www.roku.com/20201231/taxonomy/role/StatementConsolidatedStatementsOfStockholdersEquityParenthetical Consolidated Statements of Stockholders' Equity (Parenthetical) Statements 7 false false R8.htm 100070 - Statement - Consolidated Statements of Cash Flows Sheet http://www.roku.com/20201231/taxonomy/role/StatementConsolidatedStatementsOfCashFlows Consolidated Statements of Cash Flows Statements 8 false false R9.htm 100080 - Disclosure - The Company Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureTheCompany The Company Notes 9 false false R10.htm 100090 - Disclosure - Significant Accounting Policies and Basis of Presentation Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureSignificantAccountingPoliciesAndBasisOfPresentation Significant Accounting Policies and Basis of Presentation Notes 10 false false R11.htm 100100 - Disclosure - Revenue Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureRevenue Revenue Notes 11 false false R12.htm 100110 - Disclosure - Business Combination Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureBusinessCombination Business Combination Notes 12 false false R13.htm 100120 - Disclosure - Goodwill and Intangible Assets Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureGoodwillAndIntangibleAssets Goodwill and Intangible Assets Notes 13 false false R14.htm 100130 - Disclosure - Balance Sheet Components Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureBalanceSheetComponents Balance Sheet Components Notes 14 false false R15.htm 100140 - Disclosure - Licensed Content Assets Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureLicensedContentAssets Licensed Content Assets Notes 15 false false R16.htm 100150 - Disclosure - Fair Value Disclosure Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureFairValueDisclosure Fair Value Disclosure Notes 16 false false R17.htm 100160 - Disclosure - Leases Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureLeases Leases Notes 17 false false R18.htm 100170 - Disclosure - Debt Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureDebt Debt Notes 18 false false R19.htm 100180 - Disclosure - Stockholders' Equity Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureStockholdersEquity Stockholders' Equity Notes 19 false false R20.htm 100190 - Disclosure - Commitments and Contingencies Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureCommitmentsAndContingencies Commitments and Contingencies Notes 20 false false R21.htm 100200 - Disclosure - Income Taxes Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureIncomeTaxes Income Taxes Notes 21 false false R22.htm 100210 - Disclosure - Related-Party Transactions Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureRelatedPartyTransactions Related-Party Transactions Notes 22 false false R23.htm 100220 - Disclosure - Retirement Plans Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureRetirementPlans Retirement Plans Notes 23 false false R24.htm 100230 - Disclosure - Net Loss Per Share Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureNetLossPerShare Net Loss Per Share Notes 24 false false R25.htm 100240 - Disclosure - Segment Information Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureSegmentInformation Segment Information Notes 25 false false R26.htm 100250 - Disclosure - Quarterly Financial Data (Unaudited) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureQuarterlyFinancialDataUnaudited Quarterly Financial Data (Unaudited) Notes 26 false false R27.htm 100260 - Disclosure - Significant Accounting Policies and Basis of Presentation (Policies) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureSignificantAccountingPoliciesAndBasisOfPresentationPolicies Significant Accounting Policies and Basis of Presentation (Policies) Policies http://www.roku.com/20201231/taxonomy/role/DisclosureSignificantAccountingPoliciesAndBasisOfPresentation 27 false false R28.htm 100270 - Disclosure - Significant Accounting Policies and Basis of Presentation (Tables) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureSignificantAccountingPoliciesAndBasisOfPresentationTables Significant Accounting Policies and Basis of Presentation (Tables) Tables http://www.roku.com/20201231/taxonomy/role/DisclosureSignificantAccountingPoliciesAndBasisOfPresentation 28 false false R29.htm 100280 - Disclosure - Revenue (Tables) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureRevenueTables Revenue (Tables) Tables http://www.roku.com/20201231/taxonomy/role/DisclosureRevenue 29 false false R30.htm 100290 - Disclosure - Business Combination (Tables) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureBusinessCombinationTables Business Combination (Tables) Tables http://www.roku.com/20201231/taxonomy/role/DisclosureBusinessCombination 30 false false R31.htm 100300 - Disclosure - Goodwill and Intangible Assets (Tables) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureGoodwillAndIntangibleAssetsTables Goodwill and Intangible Assets (Tables) Tables http://www.roku.com/20201231/taxonomy/role/DisclosureGoodwillAndIntangibleAssets 31 false false R32.htm 100310 - Disclosure - Balance Sheet Components (Tables) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureBalanceSheetComponentsTables Balance Sheet Components (Tables) Tables http://www.roku.com/20201231/taxonomy/role/DisclosureBalanceSheetComponents 32 false false R33.htm 100320 - Disclosure - Licensed Content Assets (Tables) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureLicensedContentAssetsTables Licensed Content Assets (Tables) Tables http://www.roku.com/20201231/taxonomy/role/DisclosureLicensedContentAssets 33 false false R34.htm 100330 - Disclosure - Fair Value Disclosure (Tables) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureFairValueDisclosureTables Fair Value Disclosure (Tables) Tables http://www.roku.com/20201231/taxonomy/role/DisclosureFairValueDisclosure 34 false false R35.htm 100340 - Disclosure - Leases (Tables) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureLeasesTables Leases (Tables) Tables http://www.roku.com/20201231/taxonomy/role/DisclosureLeases 35 false false R36.htm 100350 - Disclosure - Debt (Tables) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureDebtTables Debt (Tables) Tables http://www.roku.com/20201231/taxonomy/role/DisclosureDebt 36 false false R37.htm 100360 - Disclosure - Stockholders' Equity (Tables) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureStockholdersEquityTables Stockholders' Equity (Tables) Tables http://www.roku.com/20201231/taxonomy/role/DisclosureStockholdersEquity 37 false false R38.htm 100370 - Disclosure - Income Taxes (Tables) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureIncomeTaxesTables Income Taxes (Tables) Tables http://www.roku.com/20201231/taxonomy/role/DisclosureIncomeTaxes 38 false false R39.htm 100380 - Disclosure - Net Loss Per Share (Tables) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureNetLossPerShareTables Net Loss Per Share (Tables) Tables http://www.roku.com/20201231/taxonomy/role/DisclosureNetLossPerShare 39 false false R40.htm 100390 - Disclosure - Segment Information (Tables) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureSegmentInformationTables Segment Information (Tables) Tables http://www.roku.com/20201231/taxonomy/role/DisclosureSegmentInformation 40 false false R41.htm 100400 - Disclosure - Quarterly Financial Data (Unaudited) (Tables) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureQuarterlyFinancialDataUnauditedTables Quarterly Financial Data (Unaudited) (Tables) Tables http://www.roku.com/20201231/taxonomy/role/DisclosureQuarterlyFinancialDataUnaudited 41 false false R42.htm 100410 - Disclosure - The Company - Additional Information (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureTheCompanyAdditionalInformationDetails The Company - Additional Information (Details) Details 42 false false R43.htm 100420 - Disclosure - Significant Accounting Policies and Basis of Presentation - Additional Information (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureSignificantAccountingPoliciesAndBasisOfPresentationAdditionalInformationDetails Significant Accounting Policies and Basis of Presentation - Additional Information (Details) Details 43 false false R44.htm 100430 - Disclosure - Significant Accounting Policies and Basis of Presentation - Schedule of Allowance for Sales Returns (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureSignificantAccountingPoliciesAndBasisOfPresentationScheduleOfAllowanceForSalesReturnsDetails Significant Accounting Policies and Basis of Presentation - Schedule of Allowance for Sales Returns (Details) Details 44 false false R45.htm 100440 - Disclosure - Significant Accounting Policies and Basis of Presentation - Schedule of Allowance for Sales Incentives (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureSignificantAccountingPoliciesAndBasisOfPresentationScheduleOfAllowanceForSalesIncentivesDetails Significant Accounting Policies and Basis of Presentation - Schedule of Allowance for Sales Incentives (Details) Details 45 false false R46.htm 100450 - Disclosure - Significant Accounting Policies and Basis of Presentation - Schedule of Allowance for Doubtful Accounts (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureSignificantAccountingPoliciesAndBasisOfPresentationScheduleOfAllowanceForDoubtfulAccountsDetails Significant Accounting Policies and Basis of Presentation - Schedule of Allowance for Doubtful Accounts (Details) Details 46 false false R47.htm 100460 - Disclosure - Revenue - Additional Information (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureRevenueAdditionalInformationDetails Revenue - Additional Information (Details) Details 47 false false R48.htm 100470 - Disclosure - Revenue - Schedule of Contract Balances (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureRevenueScheduleOfContractBalancesDetails Revenue - Schedule of Contract Balances (Details) Details 48 false false R49.htm 100480 - Disclosure - Business Combination - Additional Information (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureBusinessCombinationAdditionalInformationDetails Business Combination - Additional Information (Details) Details 49 false false R50.htm 100490 - Disclosure - Business Combination - Schedule of Allocation of Purchase Consideration to Tangible and Intangible Assets Acquired and Liabilities Assumed on Acquisition Date (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureBusinessCombinationScheduleOfAllocationOfPurchaseConsiderationToTangibleAndIntangibleAssetsAcquiredAndLiabilitiesAssumedOnAcquisitionDateDetails Business Combination - Schedule of Allocation of Purchase Consideration to Tangible and Intangible Assets Acquired and Liabilities Assumed on Acquisition Date (Details) Details 50 false false R51.htm 100500 - Disclosure - Goodwill and Intangible Assets - Schedule of Carrying Value of Goodwill (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureGoodwillAndIntangibleAssetsScheduleOfCarryingValueOfGoodwillDetails Goodwill and Intangible Assets - Schedule of Carrying Value of Goodwill (Details) Details 51 false false R52.htm 100510 - Disclosure - Goodwill and Intangible Assets - Additional Information (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureGoodwillAndIntangibleAssetsAdditionalInformationDetails Goodwill and Intangible Assets - Additional Information (Details) Details 52 false false R53.htm 100520 - Disclosure - Goodwill and Intangible Assets - Summary of Intangible Assets (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureGoodwillAndIntangibleAssetsSummaryOfIntangibleAssetsDetails Goodwill and Intangible Assets - Summary of Intangible Assets (Details) Details 53 false false R54.htm 100530 - Disclosure - Goodwill and Intangible Assets - Schedule of Estimated Future Amortization Expense for Intangible Asset (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureGoodwillAndIntangibleAssetsScheduleOfEstimatedFutureAmortizationExpenseForIntangibleAssetDetails Goodwill and Intangible Assets - Schedule of Estimated Future Amortization Expense for Intangible Asset (Details) Details 54 false false R55.htm 100540 - Disclosure - Balance Sheet Components - Schedule of Accounts Receivable, Net (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureBalanceSheetComponentsScheduleOfAccountsReceivableNetDetails Balance Sheet Components - Schedule of Accounts Receivable, Net (Details) Details 55 false false R56.htm 100550 - Disclosure - Balance Sheet Components - Schedule of Property and Equipment, Net (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureBalanceSheetComponentsScheduleOfPropertyAndEquipmentNetDetails Balance Sheet Components - Schedule of Property and Equipment, Net (Details) Details 56 false false R57.htm 100560 - Disclosure - Balance Sheet Components - Additional Information (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureBalanceSheetComponentsAdditionalInformationDetails Balance Sheet Components - Additional Information (Details) Details 57 false false R58.htm 100570 - Disclosure - Balance Sheet Components - Schedule of Accrued Liabilities (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureBalanceSheetComponentsScheduleOfAccruedLiabilitiesDetails Balance Sheet Components - Schedule of Accrued Liabilities (Details) Details 58 false false R59.htm 100580 - Disclosure - Balance Sheet Components - Schedule of Deferred Revenue (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureBalanceSheetComponentsScheduleOfDeferredRevenueDetails Balance Sheet Components - Schedule of Deferred Revenue (Details) Details 59 false false R60.htm 100590 - Disclosure - Licensed Content Assets - Additional Information (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureLicensedContentAssetsAdditionalInformationDetails Licensed Content Assets - Additional Information (Details) Details 60 false false R61.htm 100600 - Disclosure - Licensed Content Assets - Schedule of Amortization Expense for Licensed Content Assets (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureLicensedContentAssetsScheduleOfAmortizationExpenseForLicensedContentAssetsDetails Licensed Content Assets - Schedule of Amortization Expense for Licensed Content Assets (Details) Details 61 false false R62.htm 100610 - Disclosure - Fair Value Disclosure - Schedule of Financial Assets Measured at Fair Value (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureFairValueDisclosureScheduleOfFinancialAssetsMeasuredAtFairValueDetails Fair Value Disclosure - Schedule of Financial Assets Measured at Fair Value (Details) Details 62 false false R63.htm 100620 - Disclosure - Fair Value Disclosure - Additional Information (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureFairValueDisclosureAdditionalInformationDetails Fair Value Disclosure - Additional Information (Details) Details 63 false false R64.htm 100630 - Disclosure - Leases - Additional Information (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureLeasesAdditionalInformationDetails Leases - Additional Information (Details) Details 64 false false R65.htm 100640 - Disclosure - Leases - Schedule of Components of Lease Expense (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureLeasesScheduleOfComponentsOfLeaseExpenseDetails Leases - Schedule of Components of Lease Expense (Details) Details 65 false false R66.htm 100650 - Disclosure - Leases - Schedule of Components of Lease Expense (Parenthetical) (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureLeasesScheduleOfComponentsOfLeaseExpenseParentheticalDetails Leases - Schedule of Components of Lease Expense (Parenthetical) (Details) Details 66 false false R67.htm 100660 - Disclosure - Leases - Schedule of Supplemental Cash Flow Information Related to Leases (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureLeasesScheduleOfSupplementalCashFlowInformationRelatedToLeasesDetails Leases - Schedule of Supplemental Cash Flow Information Related to Leases (Details) Details 67 false false R68.htm 100670 - Disclosure - Leases - Schedule of Supplemental Balance Sheet Information Related to Leases (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureLeasesScheduleOfSupplementalBalanceSheetInformationRelatedToLeasesDetails Leases - Schedule of Supplemental Balance Sheet Information Related to Leases (Details) Details 68 false false R69.htm 100680 - Disclosure - Leases - Schedule of Future Lease Payments under Operating Leases (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureLeasesScheduleOfFutureLeasePaymentsUnderOperatingLeasesDetails Leases - Schedule of Future Lease Payments under Operating Leases (Details) Details 69 false false R70.htm 100700 - Disclosure - Debt - Schedule of Outstanding Debt (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureDebtScheduleOfOutstandingDebtDetails Debt - Schedule of Outstanding Debt (Details) Details 70 false false R71.htm 100710 - Disclosure - Debt - Additional Information (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureDebtAdditionalInformationDetails Debt - Additional Information (Details) Details 71 false false R72.htm 100720 - Disclosure - Stockholders' Equity - Preferred Stock - Additional Information (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureStockholdersEquityPreferredStockAdditionalInformationDetails Stockholders' Equity - Preferred Stock - Additional Information (Details) Details 72 false false R73.htm 100730 - Disclosure - Stockholders' Equity - Common Stock - Additional Information (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureStockholdersEquityCommonStockAdditionalInformationDetails Stockholders' Equity - Common Stock - Additional Information (Details) Details 73 false false R74.htm 100740 - Disclosure - Stockholders' Equity - At-the-Market Offering - Additional Information (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureStockholdersEquityAtMarketOfferingAdditionalInformationDetails Stockholders' Equity - At-the-Market Offering - Additional Information (Details) Details 74 false false R75.htm 100750 - Disclosure - Stockholders' Equity - Schedule of Reserved Shares of Common Stock for Issuance (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureStockholdersEquityScheduleOfReservedSharesOfCommonStockForIssuanceDetails Stockholders' Equity - Schedule of Reserved Shares of Common Stock for Issuance (Details) Details 75 false false R76.htm 100760 - Disclosure - Stockholders' Equity - Equity Incentive Plans - Additional Information (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureStockholdersEquityEquityIncentivePlansAdditionalInformationDetails Stockholders' Equity - Equity Incentive Plans - Additional Information (Details) Details 76 false false R77.htm 100770 - Disclosure - Stockholders' Equity - Summary of Restricted Stock Unit Activity (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureStockholdersEquitySummaryOfRestrictedStockUnitActivityDetails Stockholders' Equity - Summary of Restricted Stock Unit Activity (Details) Details 77 false false R78.htm 100780 - Disclosure - Stockholders' Equity - Restricted Stock Units - Additional Information (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureStockholdersEquityRestrictedStockUnitsAdditionalInformationDetails Stockholders' Equity - Restricted Stock Units - Additional Information (Details) Details 78 false false R79.htm 100790 - Disclosure - Stockholders' Equity - Summary of Stock Option Activity (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureStockholdersEquitySummaryOfStockOptionActivityDetails Stockholders' Equity - Summary of Stock Option Activity (Details) Details 79 false false R80.htm 100800 - Disclosure - Stockholders' Equity - Stock Option Plan - Additional Information (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureStockholdersEquityStockOptionPlanAdditionalInformationDetails Stockholders' Equity - Stock Option Plan - Additional Information (Details) Details 80 false false R81.htm 100810 - Disclosure - Stockholders' Equity - Stock-based Compensation - Additional Information (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureStockholdersEquityStockBasedCompensationAdditionalInformationDetails Stockholders' Equity - Stock-based Compensation - Additional Information (Details) Details 81 false false R82.htm 100820 - Disclosure - Stockholders' Equity - Schedule of Share-based Compensation Expense (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureStockholdersEquityScheduleOfShareBasedCompensationExpenseDetails Stockholders' Equity - Schedule of Share-based Compensation Expense (Details) Details 82 false false R83.htm 100830 - Disclosure - Stockholders' Equity - Expected Dividends - Additional Information (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureStockholdersEquityExpectedDividendsAdditionalInformationDetails Stockholders' Equity - Expected Dividends - Additional Information (Details) Details 83 false false R84.htm 100840 - Disclosure - Stockholders' Equity - Summary of Assumptions Used to Value Stock Options Granted (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureStockholdersEquitySummaryOfAssumptionsUsedToValueStockOptionsGrantedDetails Stockholders' Equity - Summary of Assumptions Used to Value Stock Options Granted (Details) Details 84 false false R85.htm 100850 - Disclosure - Commitments and Contingencies - Additional Information (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureCommitmentsAndContingenciesAdditionalInformationDetails Commitments and Contingencies - Additional Information (Details) Details 85 false false R86.htm 100860 - Disclosure - Income Taxes - Schedule of Components of Loss Before Income Taxes (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureIncomeTaxesScheduleOfComponentsOfLossBeforeIncomeTaxesDetails Income Taxes - Schedule of Components of Loss Before Income Taxes (Details) Details 86 false false R87.htm 100870 - Disclosure - Income Taxes - Schedule of Income Tax (Benefit) Expense (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureIncomeTaxesScheduleOfIncomeTaxBenefitExpenseDetails Income Taxes - Schedule of Income Tax (Benefit) Expense (Details) Details 87 false false R88.htm 100880 - Disclosure - Income Taxes - Schedule of Reconciliation of Statutory Federal Income Tax Rate to Effective Tax Rate (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureIncomeTaxesScheduleOfReconciliationOfStatutoryFederalIncomeTaxRateToEffectiveTaxRateDetails Income Taxes - Schedule of Reconciliation of Statutory Federal Income Tax Rate to Effective Tax Rate (Details) Details 88 false false R89.htm 100890 - Disclosure - Income Taxes - Summary of Significant Components of Deferred Income Tax Assets and Liabilities (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureIncomeTaxesSummaryOfSignificantComponentsOfDeferredIncomeTaxAssetsAndLiabilitiesDetails Income Taxes - Summary of Significant Components of Deferred Income Tax Assets and Liabilities (Details) Details 89 false false R90.htm 100900 - Disclosure - Income Taxes - Additional Information (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetails Income Taxes - Additional Information (Details) Details 90 false false R91.htm 100910 - Disclosure - Income Taxes - Summary of Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureIncomeTaxesSummaryOfReconciliationOfBeginningAndEndingAmountOfUnrecognizedTaxBenefitsDetails Income Taxes - Summary of Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits (Details) Details 91 false false R92.htm 100920 - Disclosure - Related-Party Transactions - Additional Information (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureRelatedPartyTransactionsAdditionalInformationDetails Related-Party Transactions - Additional Information (Details) Details 92 false false R93.htm 100930 - Disclosure - Retirement Plans - Additional Information (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureRetirementPlansAdditionalInformationDetails Retirement Plans - Additional Information (Details) Details 93 false false R94.htm 100940 - Disclosure - Net Loss Per Share - Summary of Calculation of Basic and Diluted Net Loss Per Share (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureNetLossPerShareSummaryOfCalculationOfBasicAndDilutedNetLossPerShareDetails Net Loss Per Share - Summary of Calculation of Basic and Diluted Net Loss Per Share (Details) Details 94 false false R95.htm 100950 - Disclosure - Net Loss Per Share - Schedule of Antidilutive Securities Excluded from Calculation of Diluted Net Loss Per Share (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureNetLossPerShareScheduleOfAntidilutiveSecuritiesExcludedFromCalculationOfDilutedNetLossPerShareDetails Net Loss Per Share - Schedule of Antidilutive Securities Excluded from Calculation of Diluted Net Loss Per Share (Details) Details 95 false false R96.htm 100960 - Disclosure - Segment Information - Additional Information (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureSegmentInformationAdditionalInformationDetails Segment Information - Additional Information (Details) Details 96 false false R97.htm 100970 - Disclosure - Segment Information - Schedule of Customer Accounting for 10% or More of Segment Revenue (Details) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureSegmentInformationScheduleOfCustomerAccountingFor10OrMoreOfSegmentRevenueDetails Segment Information - Schedule of Customer Accounting for 10% or More of Segment Revenue (Details) Details 97 false false R98.htm 100980 - Disclosure - 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) Sheet http://www.roku.com/20201231/taxonomy/role/DisclosureQuarterlyFinancialDataUnauditedSummaryOfCompanySInformationOnTotalRevenueGrossProfitNetIncomeLossAndEarningsPerShareByQuarterDetails 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) Details http://www.roku.com/20201231/taxonomy/role/DisclosureQuarterlyFinancialDataUnauditedTables 98 false false All Reports Book All Reports roku-10k_20201231.htm roku-20201231.xsd roku-20201231_cal.xml roku-20201231_def.xml roku-20201231_lab.xml roku-20201231_pre.xml roku-ex1012_19.htm roku-ex1013_18.htm roku-ex1014_20.htm roku-ex211_12.htm roku-ex231_6.htm roku-ex241_8.htm roku-ex311_14.htm roku-ex312_9.htm roku-ex321_10.htm roku-ex322_13.htm gs2yth4nlfsk000001.jpg gs2yth4nlfsk000002.jpg http://fasb.org/srt/2020-01-31 http://xbrl.sec.gov/dei/2020-01-31 http://fasb.org/us-gaap/2020-01-31 true true