v3.20.4

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

X
- Definition Amount of expense for award under share-based payment arrangement. Excludes amount capitalized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5047-113901 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 14.F) -URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1)(i) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_AllocatedShareBasedCompensationExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_CostOfSalesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=roku_PlatformSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=roku_PlayerSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_ResearchAndDevelopmentExpenseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_SellingAndMarketingExpenseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_GeneralAndAdministrativeExpenseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |