Statement of Earnings - Previous Revenue Recognition Effect [Abstract] Statement of Earnings - Previous Revenue Recognition Effect [Abstract] Revenue, Initial Application Period Cumulative Effect Transition [Table] Revenue, Initial Application Period Cumulative Effect Transition [Table] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Accounting Standards Update 2014-09 [Member] Accounting Standards Update 2014-09 [Member] Initial Application Period Cumulative Effect Transition [Axis] Initial Application Period Cumulative Effect Transition [Axis] Initial Application Period Cumulative Effect Transition [Domain] Initial Application Period Cumulative Effect Transition [Domain] Calculated under Revenue Guidance in Effect before Topic 606 [Member] Calculated under Revenue Guidance in Effect before Topic 606 [Member] Revenue, Initial Application Period Cumulative Effect Transition [Line Items] Revenue, Initial Application Period Cumulative Effect Transition [Line Items] Revenues Revenues Costs and Expenses Costs and Expenses Operating income Operating Income (Loss) Income Tax Expense (Benefit) Income Tax Expense (Benefit) Net earnings from continuing operations (Viacom and noncontrolling interests) Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest Net earnings (Viacom and noncontrolling interests) Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net Income (Loss) Attributable to Parent Net Income (Loss) Attributable to Parent Continuing operations (in usd per share) Income (Loss) from Continuing Operations, Per Basic Share Continuing operations (in usd per share) Income (Loss) from Continuing Operations, Per Diluted Share Statement of Financial Position [Abstract] Statement [Table] Statement [Table] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Common stock, Class A Common Class A [Member] Common stock, Class B Common Class B [Member] Statement [Line Items] Statement [Line Items] ASSETS Assets [Abstract] Current assets: Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Receivables, net Receivables, Net, Current Inventory, net Inventory, Net Prepaid and other assets Prepaid Expense and Other Assets, Current Total current assets Assets, Current Property and equipment, net Property, Plant and Equipment, Net Inventory, net Inventory, Noncurrent Goodwill Goodwill Intangibles, net Intangible Assets, Net (Excluding Goodwill) Other assets Other Assets, Noncurrent Total assets Assets LIABILITIES AND EQUITY Liabilities and Equity [Abstract] Current liabilities: Liabilities, Current [Abstract] Accounts payable Accounts Payable, Current Accrued expenses Accrued Liabilities, Current Participants' share and residuals Participants Share And Residuals Current The total amount of participations, residual and royalty expenses due to another party in less than one year. Royalty expenses are due to content creators, including artists, authors and other talent; participations includes amounts to financial participants in films, including actors, directors, and producers, for contractually defined participations in a film's net profit or gross receipts; residuals include amounts due to unions and guilds. Program obligations Program Rights Obligations Current1 Carrying value as of the balance sheet date of program rights obligations incurred and payable in less than one year. Deferred revenue Deferred Revenue, Current Current portion of debt Debt, Current Other liabilities Other Liabilities, Current Total current liabilities Liabilities, Current Noncurrent portion of debt Long-term Debt and Lease Obligation Participants' share and residuals Participants' share and residuals, noncurrent1 The total amount of participations, residual and royalty expenses due to another party outside of one year of the balance sheet date. Royalty expenses are due to content creators, including artists, authors and other talent; participations includes amounts to financial participants in films, including actors, directors, and producers, for contractually defined participations in a film's net profit or gross receipts; residuals include amounts due to unions and guilds. Program obligations Program obligations, noncurrent1 Carrying value as of the balance sheet date of program obligations incurred and payable due after one year (or beyond the operating cycle if longer). Deferred tax liabilities, net Deferred Tax Liabilities, Net, Noncurrent Other liabilities Other Liabilities, Noncurrent Redeemable noncontrolling interest Temporary Equity, Carrying Amount, Including Portion Attributable to Noncontrolling Interests Commitments and contingencies Commitments and Contingencies Viacom stockholders' equity: Stockholders' Equity Attributable to Parent [Abstract] Common stock value Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital Treasury stock, 392.5 and 393.1 common shares held in treasury, respectively Treasury Stock, Value Retained earnings Retained Earnings (Accumulated Deficit) Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Total Viacom stockholders' equity Stockholders' Equity Attributable to Parent Noncontrolling interests Stockholders' Equity Attributable to Noncontrolling Interest Total equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Total liabilities and equity Liabilities and Equity Share-based Payment Arrangement [Abstract] Compensation Cost Recognized in Earnings Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] Weighted Average Fair Value of Awards and Assumptions Weighted Average Fair Value Of Awards And Assumptions [Table Text Block] Table that displays the weighted average fair value of option grants as well as the assumptions used to in obtaining the value. These assumptions include the expected stock price volatility, expected term, expected dividend yield, and the risk free interest rate Stock Option Transactions Share-based Payment Arrangement, Option, Activity [Table Text Block] Stock Option Exercises Stock Option Exercises [Table Text Block] Table that displays the information related to stock option exercises, including proceeds from exercises, intrinsic value, and tax benefits received. Share Units Rollforward Of Rsu Psu Prsu Outstanding [Table Text Block] Table that displays changes in restricted share units, performance share units and performance-based restructured share units from share-based arrangements under which compensation is awarded to employees. Comprised of changes in the quantity of the units granted, vested, and forfeited. Provides totals of those outstanding and unvested at the end of the period. All categories include the weighted average grant date fair value of the units within the related group. Goodwill and Intangible Assets Disclosure [Abstract] Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Trade names Trade Names [Member] [Member] Trade Names Member Licenses Licenses [Member] Licenses Member Subscriber agreements Subscriber Agreements [Member] Gross carrying amount before accumulated amortization as of the balance sheet of intangible assets related to subscriber agreements. Other intangible assets Other Intangible assets member [Member] Other Intangible assets Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Finite lived intangible assets - gross Finite-Lived Intangible Assets, Gross Finite lived intangible assets - accumulated amortization Finite-Lived Intangible Assets, Accumulated Amortization Finite-lived intangible assets, net Finite-Lived Intangible Assets, Net Indefinite-lived intangible assets Indefinite-lived Intangible Assets (Excluding Goodwill) Total intangibles, net Income Tax Disclosure [Abstract] Income Taxes Income Tax Disclosure [Text Block] Commitments and Contingencies Disclosure [Abstract] Other Commitments [Table] Other Commitments [Table] Balance Sheet Recognition, Type [Axis] Balance Sheet Recognition, Type [Axis] Balance Sheet Recognition, Type [Axis] Balance Sheet Recognition, Type [Domain] Balance Sheet Recognition, Type [Domain] [Domain] for Balance Sheet Recognition, Type [Axis] Off-Balance Sheet Arrangements Off-Balance Sheet Arrangements [Member] Off-Balance Sheet Arrangements [Member] On-Balance Sheet Arrangements On-Balance Sheet Arrangements [Member] On-Balance Sheet Arrangements [Member] Other Commitments [Axis] Other Commitments [Axis] Other Commitments [Domain] Other Commitments [Domain] Programming and Talent Commitments Programming And Talent Commitments [Member] Programming and talent commitments include, but not limited to, Media Networks programming and talent contracts. Operating Leases Operating Leases [Member] Operating leases include, but not limited to, long-term non-cancelable operating lease commitments for office space, equipment, transponders, studio facilities, and vehicles. Purchase Obligations Purchase Commitments, Including Long-Term Commitments [Member] Purchase arrangement in which the entity has agreed to expend funds to procure goods or services from a supplier, including, but not limited to, long-term commitments and open purchase orders. Capital Lease Obligations Capital Lease Obligations [Member] Debt Debt [Member] Interest Payments Interest Payments [Member] Interest payment obligations on a cash basis. Other Long-Term Obligations Other Long-Term Obligations [Member] Other long-term obligations principally consist of, but not limited to, participations, residuals and programming obligations for content that is available for airing. Programming and Talent Commitments [Axis] Programming and Talent Commitments [Axis] Programming and Talent Commitments [Axis] Programming and Talent Commitments [Domain] Programming and Talent Commitments [Domain] [Domain] for Programming and Talent Commitments [Axis] Media Networks Programming Commitments Media Networks Programming Commitments [Member] Media Networks Programming Commitments [Member] Talent Contracts Commitments Talent Contracts Commitments [Member] As of the balance sheet date, total of talent contracts not recorded on the balance sheet. Other Commitments [Line Items] Other Commitments [Line Items] Contractual Obligation Contractual Obligation Contractual Obligation, Due in Next Fiscal Year Contractual Obligation, Due in Next Fiscal Year Contractual Obligation, Due in Second Year Contractual Obligation, Due in Second Year Contractual Obligation, Due in Third Year Contractual Obligation, Due in Third Year Contractual Obligation, Due in Fourth Year Contractual Obligation, Due in Fourth Year Contractual Obligation, Due in Fifth Year Contractual Obligation, Due in Fifth Year Contractual Obligation, Due after Fifth Year Contractual Obligation, Due after Fifth Year Segment Reporting [Abstract] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Media Networks Media Networks [Member] Media Networks Filmed Entertainment Film Entertainment [Member] Film Entertainment Corporate expenses Corporate Segment [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Total assets Property, Plant and Equipment [Abstract] Property And Equipment Property, Plant and Equipment Disclosure [Text Block] Accounting Policies [Abstract] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Schedule of Goodwill [Table] Schedule of Goodwill [Table] Media Networks Media Network [Member] Media Networks segment goodwill Filmed Entertainment Filmed Entertainment [Member] Filmed Entertainment Goodwill [Line Items] Goodwill [Line Items] Goodwill [Roll Forward] Goodwill [Roll Forward] Beginning balance Acquisitions Goodwill, Acquired During Period Foreign currency translation Goodwill, Foreign Currency Translation Gain (Loss) Ending balance Weighted average fair value of grants Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Weighted average assumptions: Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract] Expected stock price volatility Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate Expected term of options (in years) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Risk-free interest rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Expected dividend yield Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate Current provision for income taxes: Components of Income Tax Expense (Benefit), Continuing Operations [Abstract] Federal Current Federal Tax Expense (Benefit) State and local Current State and Local Tax Expense (Benefit) International Current Foreign Tax Expense (Benefit) Total current provision for income taxes Current Income Tax Expense (Benefit) Deferred provision for income taxes Deferred Other Tax Expense (Benefit) Provision for income taxes Acquisition [Abstract] Acquisition [Abstract] Pluto TV Purchase Price Allocation Schedule of Business Acquisitions, by Acquisition [Table Text Block] Retirement Benefits [Abstract] Schedule of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [Table] Retirement Plan Funding Status [Axis] Retirement Plan Funding Status [Axis] Retirement Plan Funding Status [Domain] Retirement Plan Funding Status [Domain] Funded Plan [Member] Funded Plan [Member] Unfunded Plan [Member] Unfunded Plan [Member] Accumulated Benefit Obligation [Axis] Accumulated Benefit Obligation [Axis] -- None. No documentation exists for this element. -- Accumulated Benefit Obligation [Domain] Accumulated Benefit Obligation [Domain] -- None. No documentation exists for this element. -- Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Accumulated benefit obligation Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Accumulated Benefit Obligation Fair value of plan assets DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssetsIncludingAssetsMeasuredAtNetAssetValuePerShare Fair value of plan assets for defined benefit pension plan with accumulated benefit obligation in excess of plan assets, including assets that are measured at net asset value per share and excluded from the fair value hierarchy as permitted under a practical expedient. Funded status Defined Benefit Plan, Funded (Unfunded) Status of Plan Income Tax Contingency [Table] Income Tax Contingency [Table] Income Tax Authority [Axis] Income Tax Authority [Axis] Income Tax Authority [Domain] Income Tax Authority [Domain] The Act [Member] The Act [Member] The Act [Member] United States UNITED STATES Foreign Tax Authority [Member] Foreign Tax Authority [Member] Income Tax Authority, Name [Axis] Income Tax Authority, Name [Axis] Income Tax Authority, Name [Domain] Income Tax Authority, Name [Domain] Tax Period [Axis] Tax Period [Axis] Tax Period [Domain] Tax Period [Domain] Income Tax Contingency [Line Items] Income Tax Contingency [Line Items] Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Operating Loss Carryforwards Operating Loss Carryforwards Recognized Net Discrete Tax Benefits Recognized Net Discrete Tax Benefits Net discrete tax benefits recognized in the period. Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Amount Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Amount Foreign Tax Losses With Unlimited Carryforward Periods Foreign Tax Losses With Unlimited Carryforward Periods Aggregate foreign tax losses with unlimited carry forward periods at the balance sheet date. Foreign Tax Losses With Limited Carryforward Periods Foreign Tax Losses With Limited Carryforward Periods Aggregate foreign tax losses with limited carry forward periods at the balance sheet date. Tax credit and loss carryforwards Deferred Tax Assets Tax Credit And Loss Carryforwards The tax effect as of the balance sheet date of the amount of estimated future tax deductions arising from tax credit and loss carryforwards, which can only be deducted for tax purposes when actual costs are incurred, and which can only be realized if sufficient tax-basis income is generated in future periods to enable the deduction to be taken. Foreign Earnings Repatriated Foreign Earnings Repatriated Interest and Penalties Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense Interest and Penalties Accrual Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued Future Unrecognized tax benefits Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit Entity Wide Disclosure On Geographic Areas Revenue And Long Lived Assets From External Customers Attributed To Individual Foreign Countries [Axis] Entity Wide Disclosure On Geographic Areas Revenue And Long Lived Assets From External Customers Attributed To Individual Foreign Countries [Axis] -- None. No documentation exists for this element. -- Geographical [Domain] Geographical [Domain] EMEA EMEA [Member] All other All Other [Member] -- None. No documentation exists for this element. -- Long-Lived Assets Long-Lived Assets Defined Contribution Plan, Cost Defined Contribution Plan, Cost Statistical Measurement [Axis] Statistical Measurement [Axis] Statistical Measurement [Domain] Statistical Measurement [Domain] Minimum Minimum [Member] Maximum [Member] Maximum [Member] Defined Benefit Plan, Plan Assets, Category [Axis] Defined Benefit Plan, Plan Assets, Category [Axis] Defined Benefit Plan, Plan Assets, Category [Domain] Defined Benefit Plan, Plan Assets, Category [Domain] Return seeking Equity Securities [Member] Liability hedging Debt Securities [Member] Cash and cash equivalents Cash and Cash Equivalents [Member] Defined Benefit Plan, Plan Assets, Target Allocation, Percentage Defined Benefit Plan, Plan Assets, Target Allocation, Percentage Percent Of Plan Assets Of Company Stock Percent Of Plan Assets Of Company Stock Percent of Company stock represented in the fair value of plan assets Statement of Stockholders' Equity [Abstract] Accounting Standards Update 2018-02 [Member] ASU 2018-02 [Member] ASU 2018-02 [Member] ASC 606, ASU 2016-16 and ASU 2016-01, Shares [Member] ASC 606, ASU 2016-16 and ASU 2016-01, Shares [Member] ASC 606, ASU 2016-16 and ASU 2016-01, Shares [Member] ASC 606, ASU 2016-16 and ASU 2016-01 [Member] ASC 606, ASU 2016-16 and ASU 2016-01 [Member] ASC 606, ASU 2016-16 and ASU 2016-01 [Member] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common Stock (shares) Common Stock [Member] Common Stock/ Additional Paid-In Capital Common Stock Including Additional Paid in Capital [Member] Treasury Stock Treasury Stock [Member] Retained Earnings Retained Earnings [Member] Accumulated Other Comprehensive Loss AOCI Attributable to Parent [Member] Total Viacom Stockholders’ Equity Parent [Member] Noncontrolling Interests Noncontrolling Interest [Member] Equity, at beginning of period Shares issued, at beginning of period Shares, Issued Net earnings Profit Loss S C I The consolidated profit/loss, for the period, net of tax, related to the Parent and Noncontrolling interests, excluding income/loss related to the redeemable noncontrolling interest in temporary equity. Other comprehensive income (loss), net of income tax benefit / expense Other Comprehensive Income (Loss), Net of Tax Noncontrolling interests Noncontrolling interest Represents the total impact of the noncontrolling interests to the parent company's records Dividends declared ($0.80 per share for both Class A and Class B) Dividends, Common Stock, Cash Equity-based compensation and other Equity Based Compensation And Other Value Net change to common stock and additional paid-in capital during the period related to equity-based compensation and other. Equity based compensation and other, shares Equity Based Compensation And Other Shares Net change to common stock and additional paid-in capital related to equity based compensation Equity, at end of period Shares issued, at end of period Adoption of New Accounting Pronouncements(2) Cumulative Effect on Retained Earnings, Net of Tax Stock Issued During Period, Shares, Issued for Services Stock Issued During Period, Shares, Issued for Services 2020 Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months 2021 Defined Benefit Plan, Expected Future Benefit Payment, Year Two 2022 Defined Benefit Plan, Expected Future Benefit Payment, Year Three 2023 Defined Benefit Plan, Expected Future Benefit Payment, Year Four 2024 Defined Benefit Plan, Expected Future Benefit Payment, Year Five 2025 - 2029 Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter Equity [Abstract] Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Common Class A Common Class B Class of Stock [Line Items] Class of Stock [Line Items] Common Stock Authorized Common Stock, Shares Authorized Minimum Class A Shares Needed For Conversion Minimum Shares Needed For Conversion Minimum number of Class A common shares required to be outstanding in order for Class A common shares to be convertible to Class B shares. Common stock conversion shares Common stock conversion shares Number of shares of Class B common stock converted from Class A common shares. Preferred Stock Shares Authorized Preferred Stock, Shares Authorized Preferred Stock Par Or Stated Value Per Share Preferred Stock, Par or Stated Value Per Share Preferred Stock Shares Outstanding Preferred Stock, Shares Outstanding Stock repurchase program remaining capacity Stock Repurchase Program, Remaining Authorized Repurchase Amount Stock repurchase program authorized amount Stock Repurchase Program, Authorized Amount Treasury Stock, Shares, Acquired Treasury Stock, Shares, Acquired Purchase of treasury stock Treasury Stock, Value, Acquired, Cost Method Accumulated Other Comprehensive Loss Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Restructuring and Related Activities [Abstract] Restructuring and other corporate matters (Table) Schedule of Restructuring Reserve by Type of Cost [Table Text Block] Severance Liability Rollforward (Table) Restructuring and Related Costs [Table Text Block] Restructuring and Programming Charges Restructuring and Related Activities Disclosure [Text Block] Quarterly Financial Information Disclosure [Abstract] Quarterly Financial Data (unaudited) Quarterly Financial Information [Text Block] Statement of Comprehensive Income [Abstract] Net actuarial loss Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax Recognized actuarial loss Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax Total pre-tax loss Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax Revenue from Contract with Customer [Abstract] Revenues Note [Text Block] Revenue from Contract with Customer [Text Block] Earnings Per Share [Abstract] Earnings Per Share Earnings Per Share [Text Block] Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table] Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table] Restructuring Type [Axis] Restructuring Type [Axis] Type of Restructuring [Domain] Type of Restructuring [Domain] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Stock options Share-based Payment Arrangement, Option [Member] Share units Rsu Psu Prsu [Member] -- None. No documentation exists for this element. -- Compensation cost included in SG&A expense Selling, General and Administrative Expenses [Member] Restructuring Charges [Member] Restructuring Charges [Member] Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] Recognized in earnings Share-based Payment Arrangement, Expense Restructuring and Other Corporate Matters Expense Restructuring and Other Corporate Matters Expense Amounts charged against earnings in the period for a specified incurred and estimated type of cost associated with exit from a disposal of business activities or restructuring pursuant to a duly authorized plan. Tax benefit recognized Share-based Payment Arrangement, Expense, Tax Benefit Capitalized equity-based compensation expense Share-based Payment Arrangement, Amount Capitalized Inventory Disclosure [Abstract] Schedule of Product Information [Table] Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] Film Inventory Film Inventory [Member] -- None. No documentation exists for this element. -- Television Productions TelevisionProductions [Member] Television Productions [Member] Original Programming Original Programming [Member] -- None. No documentation exists for this element. -- Inventory Net [Line Items] Product Information [Line Items] Total Inventory, Net Of Amortization Total Inventory Net Of Amortization Carrying amount of total inventory, including film, television, programming, and other, net of amortization. Film inventory: Film Inventory [Abstract] Film Inventory [Abstract] Released, net of amortization Theatrical Film Costs, Released Completed, not yet released Theatrical Film Costs, Completed and Not Released In process and other Theatrical Film Costs, Production Television production: Television Productions [Abstract] Television Productions [Abstract] Released, net of amortization Released T P Net Of Amortization Carrying amount of completed and released of television production inventory. In process and other In Process And Other T P Carrying amount of television production in process and other inventory. Original programming: Original Programming [Abstract] Original Programming [Abstract] Released, net of amortization Released O P Net Of Amortization Carrying amount of completed and released of original programming inventory. In process and other In Process And Other O P Carrying amount of original programming in process and other inventory. Acquired program rights, net of amortization Acquired Program Rights Net Of Amortization Carrying amount of total acquired programming inventory. Home entertainment inventory Home Entertainment Inventory Net Of Allowances Carrying amount of consumer products inventories and other amounts that cannot be categorized by the other inventory line items, net of allowances. Total inventory, net Total Inventory Net Carrying amount of total inventory, net of allowances. Less current portion Noncurrent portion Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Noncontrolling Interest [Abstract] Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward] Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward] Beginning balance Net earnings Redeemable Noncontrolling Interest Net Earnings Net earnings attributable to the redeemable noncontrolling interest. Distributions Redeemable Noncontrolling Interest Distributions Distributions to the redeemable noncontrolling interest holder. Translation adjustment Redeemable Noncontrolling Interest Translation Adjustments Amount of translation adjustments attributable to the redeemable noncontrolling interest. Redemption value adjustment Noncontrolling Interest, Change in Redemption Value Ending balance Principles of Consolidation Consolidation, Subsidiaries or Other Investments, Consolidated Entities, Policy [Policy Text Block] Business Combinations Business Combinations Policy [Policy Text Block] Foreign Currency Translation and Remeasurement Foreign Currency Transactions and Translations Policy [Policy Text Block] Revenue Recognition Revenue [Policy Text Block] Revenue Allowances Sales Returns Allowances And Uncollectible Accounts Policy [Policy Text Block] Describes an entity's accounting policy for sales returns (where a customer has a right of return), allowances and uncollectible accounts Advertising Expense Advertising Cost [Policy Text Block] Equity-Based Compensation Share-based Payment Arrangement [Policy Text Block] Income Taxes Provision For Income Taxes Policy [Policy Text Block] Describes an entity's accounting policy for income taxes, which may include its accounting policies for recognizing and measuring deferred tax assets and liabilities and related valuation allowances, recognizing investment tax credits, operating loss carryforwards, tax credit carryforwards, and other carryforwards, methodologies for determining its effective income tax rate and the characterization of interest and penalties in the financial statements. Also describes an entity's accounting policy for tax positions taken in the Company's tax return filed or to be filed for which it is more likely than not that the tax position will not be sustained upon examination by taxing authorities (i.e., uncertain tax positions) and other types of contingencies related to income taxes. Earnings Per Common Share Earnings Per Share, Policy [Policy Text Block] Comprehensive Income Comprehensive Income, Policy [Policy Text Block] Cash and Cash Equivalents Cash and Cash Equivalents, Unrestricted Cash and Cash Equivalents, Policy [Policy Text Block] Inventory Inventory, Major Classes, Policy [Policy Text Block] Property and Equipment Property, Plant and Equipment, Policy [Policy Text Block] Goodwill, Intangible Assets and Other Long-Lived Assets Impairment Policy [Policy Text Block] Describes an entity's accounting policy for recognizing and measuring the impairment of intangible assets, long-lived assets, goodwill and indefinite-lived intangible assets. Investments Equity and Cost Method Investments, Policy [Policy Text Block] Guarantees Guarantees, Indemnifications and Warranties Policies [Policy Text Block] Treasury Stock Treasury Stock Policy [Policy Text Block] Describes the Company's accounting policy for the repurchase of the entity's common stock Fair Value Measurements Fair Value Of Financial And Non Financial Instruments Policy [Policy Text Block] Describes an entity's accounting policy for determining the fair value of its financial and non-financial instruments. Derivative Financial Instruments Derivatives, Policy [Policy Text Block] Pension Benefits Pension and Other Postretirement Plans, Policy [Policy Text Block] SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract] Schedule Of Valuation And Qualifying Accounts [Abstract] Schedule Of Valuation And Qualifying Accounts [Abstract] -- None. No documentation exists for this element. -- SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Table] SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Table] SEC Schedule, 12-09, Valuation Allowances and Reserves Type [Axis] SEC Schedule, 12-09, Valuation Allowances and Reserves Type [Axis] SEC Schedule, 12-09, Valuation Allowances and Reserves [Domain] SEC Schedule, 12-09, Valuation Allowances and Reserves [Domain] Allowance for doubtful accounts SEC Schedule, 12-09, Allowance, Credit Loss [Member] Sales Returns and Allowances Sales Returns and Allowances [Member] Deferred tax valuation allowance SEC Schedule, 12-09, Valuation Allowance, Deferred Tax Asset [Member] Valuation And Qualifying Accounts Disclosure [Line Items] SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items] SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] Beginning of period SEC Schedule, 12-09, Valuation Allowances and Reserves, Amount Additions - expense and other SEC Schedule, 12-09, Valuation Allowances and Reserves, Additions, Charge to Cost and Expense Deductions SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction End of period Deferred tax assets: Deferred Tax Assets, Net [Abstract] Accrued liabilities Deferred Tax Assets, Tax Deferred Expense Postretirement and other employee benefits Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Postretirement Benefits All other Deferred Tax Assets, Other Total deferred tax assets Deferred Tax Assets, Gross Valuation allowance Deferred Tax Assets, Valuation Allowance Total deferred tax assets, net Deferred Tax Assets, Net Deferred tax liabilities: Deferred Tax Liabilities, Gross [Abstract] Property, equipment and intangible assets Deferred Tax Liabilities Property Plant And Equipment And Intangibles The amount as of the balance sheet date of the estimated future tax effects attributable to the difference between the tax basis of capital and intangible assets and the basis of those assets computed in accordance with generally accepted accounting principles. Unbilled revenue Deferred Credits and Other Liabilities Financing obligations Deferred Tax Liabilities Financing Obligations The amount as of the balance sheet date of the estimated future tax effects attributable to the difference between the tax basis of certain financial obligations and the basis of those obligations computed in accordance with generally accepted accounting principles. Film & TV production expenditures Deferred Tax Liabilities Film And Tv Assets -- None. No documentation exists for this element. -- Total deferred tax liabilities Deferred Tax Liabilities, Gross Deferred taxes, net Deferred Income Tax Liabilities, Net Inventory Inventory Disclosure [Table Text Block] Represents the table of the major classes of inventory. Change in Benefit Obligation Schedule of Changes in Projected Benefit Obligations [Table Text Block] Change in Plan Assets Schedule of Changes in Fair Value of Plan Assets [Table Text Block] Funded Status Schedule of Net Funded Status [Table Text Block] Accumulated Benefit Obligation Schedule of Changes in Accumulated Postemployment Benefit Obligations [Table Text Block] Net Periodic Benefit Costs Schedule of Net Benefit Costs [Table Text Block] Unrecognized Benefit Cost Schedule of Net Periodic Benefit Cost Not yet Recognized [Table Text Block] Other Comprehensive Income Schedule of Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block] Key Assumptions Defined Benefit Plan, Assumptions [Table Text Block] Asset Allocations of Funded Pension Plan Schedule of Percent Allocation of Plan Assets [Table Text Block] Disclosure of the major categories of plan assets of pension plans and/or other employee benefit plans. This information is displayed by the target allocation of plan assets. Fair Value of Plan Assets Schedule of Allocation of Plan Assets [Table Text Block] Future Benefit Payments Schedule of Expected Benefit Payments [Table Text Block] Inventory [Abstract] Inventory [Abstract] Scenario [Axis] Scenario [Axis] Scenario [Domain] Scenario [Domain] Amortization Of Inventory Costs In Upcoming Fiscal Year Amortization Of Inventory Costs In Upcoming Fiscal Year Amount of original programming and film inventory, including released and completed, not yet released, expected to be amortized in the next operating cycle. Percent To Be Amortized Over Three Years Of Inventory Costs Percent To Be Amortized Over Three Years Of Inventory Costs The percentage of unamortized released original programming and film inventory, excluding acquired film libraries, that it expects to amortize within three years from the date of the balance sheet. Unamortized Inventory In Years Unamortized Inventory In Years Expected term in years to amortize inventory, excluding acquired film libraries. Programming charges Programming inventory restructure Amounts charged against earnings in the period for programming inventory restructuring associated with restructuring pursuant to a duly authorized plan. Quarterly Financial Data Quarterly Financial Information [Table Text Block] Eliminations Reconciling Items Revenue Total of reconciling items between total reportable segments' revenues and consolidated entity revenues. Schedule of Restructuring and Related Costs [Table] Schedule of Restructuring and Related Costs [Table] Restructuring Plan [Axis] Restructuring Plan [Axis] Restructuring Plan [Domain] Restructuring Plan [Domain] 2018 Restructuring Plan [Member] 2018 Restructuring Plan [Member] 2018 Restructuring Plan [Member] Pending Merger [Member] Pending Merger [Member] Pending Merger [Member] Employee Severance [Member] Employee Severance [Member] Other Related Costs [Member] Other Related Costs [Member] Other restructuring related costs [Member] Legal Settlement [Member] Legal Settlement [Member] Legal Settlement [Member] [Member] Merger-related costs [Member] Merger-related costs [Member] Merger-related costs [Member] Allocated Share-Based Compensation Expense Allocated Share-Based Compensation Expense [Member] Allocated Share-Based Compensation Expense Other Restructuring Plans [Axis] Other Restructuring Plans [Axis] Axis of other restructuring plans table. Other Restructuring Plans [Domain] Other Restructuring Plans [Domain] Domain of other restructuring plans table. Restructuring Cost and Reserve [Line Items] Restructuring Cost and Reserve [Line Items] Restructuring and other corporate matters Restructuring Reserve Restructuring Reserve Restructuring Reserve, Current Restructuring Reserve, Current Restructuring Reserve, Noncurrent Restructuring Reserve, Noncurrent Restructuring Reserve Settled with Cash Exit Costs Restructuring Reserve Settled with Cash Exit Costs Amount of cash paid in the period related to exit costs. Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] Benefit obligation, beginning of period Defined Benefit Plan, Benefit Obligation Interest cost Defined Benefit Plan, Interest Cost Actuarial loss/(gain) Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss) Benefits paid Defined Benefit Plan, Benefit Obligation, Benefits Paid Benefit obligation, end of period Operating income Net earnings from continuing operations (Viacom and noncontrolling interests) Net earnings (Viacom and noncontrolling interests) Net earnings from continuing operations Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent Net earnings attributable to Viacom Basic earnings per share, continuing operations attributable to Viacom (in usd per share) Basic earnings per share attributable to Viacom (in usd per share) Earnings Per Share, Basic Diluted earnings per share, continuing operations attributable to Viacom (in usd per share) Diluted earnings per share attributable to Viacom (in usd per share) Earnings Per Share, Diluted Income taxes [Table] Income taxes [Table] Income taxes related disclosure [Table] Range Tax [Axis] Range Tax [Axis] Range Tax [Axis] Range Tax [Domain] Range Tax [Domain] [Domain] for Range Tax [Axis] Income taxes [Line Items] Income taxes [Line Items] [Line Items] for Income taxes related disclosure [Table] Deferred Tax Assets and Liabilities included in the Balance Sheets [Table Text Block] Deferred Tax Assets and Liabilities included in the Balance Sheets [Table Text Block] Deferred Tax Assets and Liabilities included in the Balance Sheets [Table Text Block] Earnings from Continuing Operations before Provision for Income Taxes Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block] Provision for Income Taxes from Continuing Operations Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Effective Tax Rate Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Deferred Tax Assets / (Liabilities) Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Unrecognized Tax Benefits Summary of Tax Credit Carryforwards [Table Text Block] Redeemable Noncontrolling Interest Noncontrolling Interest Disclosure [Text Block] Property and Equipment [Abstract] Property and Equipment [Abstract] Depreciation expense Depreciation, Nonproduction Amortization of capital leases Capital Leases, Income Statement, Amortization Expense Accumulated amortization of capital leases Capital Leases, Lessee Balance Sheet, Assets by Major Class, Accumulated Depreciation Allocated Share-Based Compensation Expense [Member] Operating Expense [Member] Operating Expense [Member] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Eliminations Intersegment Eliminations [Member] Adjusted operating income by Segment Segment Reporting Operating Income Loss Amount of income or loss for the reportable segment before equity-based compensation, unusual Items, equity method income or loss, income taxes, extraordinary items and certain other items identified as affecting comparability, including restructuring charges and asset impairment, when applicable. Corporate expenses Reconciling Item For Operating Profit Loss From Segment To Consolidated Amount Amount of an item in the reconciliation of total profit or loss from reportable segments, to the entity's consolidated income before income taxes, extraordinary items, discontinued operations. Eliminations Segment Reporting Reconciling Items Operating Income Intercompany eliminations used in calculating consolidated operating income. Equity-based compensation Programming charges Restructuring and Other Corporate Matters Expense Gain on asset sale Gain (Loss) on Disposition of Intangible Assets Operating income Interest expense, net Interest expense, net Interest related to total debt, bank fees and issuance fees, less interest income Equity in net earnings of investee companies Income (Loss) from Equity Method Investments Gain on sale of EPIX Equity Method Investment, Realized Gain (Loss) on Disposal Other items, net Other Nonoperating Income (Expense) Earnings from continuing operations before provision for income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Debt Disclosure [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Junior Debentures And Senior Notes Junior Debentures And Senior Notes [Member] Junior Debentures And Senior Notes Senior Notes due February 2022, 2.250% and October 2026, 3.450% Senior Notes Subject to Interest Rate Adjustments Based on Credit Rating [Member] Senior Notes Subject to Interest Rate Adjustments Based on Credit Rating [Member] Senior Notes and Senior and Junior Debentures Senior Notes and Senior and Junior Debentures [Member] Senior Notes and Senior and Junior Debentures [Member] Junior subordinated debentures due February 2057, 5.875% Junior Subordinated Debentures February 2057, 5-Year Hybrid [Member] Junior Subordinated Debentures February 2057, 5-Year Hybrid [Member] Junior subordinated debentures due February 2057, 6.250% Junior Subordinated Debenture February 2057, 10-Year Hybrid [Member] Junior Subordinated Debenture February 2057, 10-Year Hybrid [Member] Senior notes due February 2022, 2.250% Senior Notes February 2022 [Member] Senior Notes due February 2022 at a discount rate of 2.250% Senior notes due October 2026, 3.450% Senior Notes due October 2026 [Member] Senior Notes due October 2026 at a discount rate of 3.450% Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] London Interbank Offered Rate (LIBOR) [Member] London Interbank Offered Rate (LIBOR) [Member] Debt Instrument, Redemption, Period [Axis] Debt Instrument, Redemption, Period [Axis] Debt Instrument, Redemption, Period [Domain] Debt Instrument, Redemption, Period [Domain] Debt Instrument [Line Items] Debt Instrument [Line Items] Extinguishment of Debt, Amount Extinguishment of Debt, Amount Repayments of Debt Repayments of Debt Gain (Loss) on Extinguishment of Debt Gain (Loss) on Extinguishment of Debt Write off of Deferred Debt Issuance Cost Write off of Deferred Debt Issuance Cost Debt Instrument, Face Amount Debt Instrument, Face Amount Coupon rate Debt Instrument, Interest Rate, Stated Percentage Debt Instrument, Interest Rate Terms Debt Instrument, Interest Rate Terms Unamortized net discount related to senior notes and debentures Debt Instrument, Unamortized Discount (Premium), Net Fair value of senior notes and debentures Debt Instrument, Fair Value Disclosure Inventory Inventory Disclosure [Text Block] Goodwill And Intangibles Goodwill and Intangible Assets Disclosure [Text Block] Treasury Shares Treasury Stock, Shares Common stock, par value Common Stock, Par or Stated Value Per Share Common stock, outstanding Common Stock, Shares, Outstanding Business Combinations [Abstract] Acquisition and Investments AcquisitionandInvestmentsTextBlock Description of a business combination (or series of individually immaterial business combinations) completed during the period, including background, timing, and recognized assets and liabilities. This element may be used as a single block of text to encapsulate the entire disclosure (including data and tables) regarding business combinations, including leverage buyout transactions (as applicable). This disclosure also includes equity investments, or group of investments for which combined disclosure is appropriate, including: (a) the name of each investee and percentage of ownership of common stock, (b) accounting policies for investments in common stock, (c) difference between the amount at which the investment is carried and the amount of underlying equity in net assets and the accounting treatment of the difference, (d) the total fair value of each identified investment for which a market value is available, (e) summarized information as to assets, liabilities, and results of operations of the investees (for investments in unconsolidated subsidiaries, common stock of joint ventures, or other investments using the equity method), and (f) material effects of possible conversions, exercises, or contingent issuances of the investee. Other disclosures include (a) the names of any investee in which the investor owns 20 percent or more of the voting stock and investment is not accounted for using the equity method, and the reasons why not, and (b) the names of any investee in which the investor owns less than 20% of the voting stock and the investment is accounted for using the equity method, and the reasons why it is. Additionally, this disclosure includes activity related to variable interest entities (VIE), including, but not limited to the nature, purpose, size, and activities of the VIE, the carrying amount and classification of consolidated assets that are collateral for the VIE's obligations, lack of recourse if creditors (or beneficial interest holders) of a consolidated VIE have no recourse to the general credit of the primary beneficiary. An enterprise that holds a significant variable interest in a VIE but is not the primary beneficiary may disclose the nature of its involvement with the VIE and when that involvement began, the nature, purpose, size, and activities of the VIE and the enterprise's maximum exposure to loss as a result of its involvement with the VIE. Revenue from Contract with Customer - Tables - PL & SOE [Abstract] Revenue from Contract with Customer - Tables - PL & SOE [Abstract] Statement of Earnings Under Previous Revenue Recognition Guidance [Table Text Block] Statement of Earnings Under Previous Revenue Recognition Guidance [Table Text Block] [Table Text Block] for Statement of Earnings Under Previous Revenue Recognition Guidance [Table] Balance Sheet Effect Under Previous Revenue Recognition Guidance [Table Text Block] Balance Sheet Effect Under Previous Revenue Recognition Guidance [Table Text Block] [Table Text Block] for Balance Sheet Effect Under Previous Revenue Recognition Guidance [Table] Corporate Corporate1 [Member] Corporate Member Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Other Exit Activities Other Exit Activities [Member] Other exit activities associated with restructuring. Asset Impairment Asset Impairment Associated with Restructuring [Member] Asset Impairment Associated with Restructuring [Member] Contract Termination [Member] Contract Termination [Member] Property, Plant and Equipment [Table] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Land Land [Member] Buildings Building [Member] Capital leases Assets Held under Capital Leases [Member] Equipment and other Equipment [Member] Property Plant And Equipment [Line Items] Property, Plant and Equipment [Line Items] Property and equipment gross Property, Plant and Equipment, Gross Accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Property and equipment, net Property, Plant and Equipment, Useful Life Property, Plant and Equipment, Useful Life Funded status Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Balance at beginning of the period Unrecognized Tax Benefits Gross additions based on tax positions related to the current year Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions Gross additions for tax positions of prior years Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions Gross reductions for tax positions of prior years Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions Settlements Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities Expiration of the statute of limitation Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations Balance at end of the period Organization, Consolidation and Presentation of Financial Statements [Abstract] Basis of Presentation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Balance Sheet1 - Previous Revenue Recognition effect [Abstract] Balance Sheet - Previous Revenue Recognition effect [Abstract] Receivables, Net, Current Prepaid Expense and Other Assets, Current Other Assets, Noncurrent Accrued Liabilities, Current Participants Share And Residuals Current Other Liabilities, Current Participants' share and residuals, noncurrent1 Other Liabilities, Noncurrent Retained earnings Schedule II - Valuation And Qualifying Accounts SEC Schedule, 12-09, Schedule of Valuation and Qualifying Accounts Disclosure [Text Block] CBS Merger Agreement [Abstract] CBS Merger Agreement [Abstract] CBS Merger Agreement [Text Block] CBS Merger Agreement [Text Block] CBS Merger Agreement [Text Block] Related Party Transactions [Abstract] Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] CBS CBS [Member] -- None. No documentation exists for this element. -- Other Related Parties Other Related Parties [Member] -- None. No documentation exists for this element. -- Related Party Transaction [Line Items] Related Party Transaction [Line Items] Related Persons Transactions Disclosure [Table Text Block] Related Persons Transactions Disclosure [Table Text Block] A tabular disclosure of related party transactions with a related party. Related Parties Transactions Disclosure [Table Text Block] Related Parties Transactions Disclosure [Table Text Block] A tabular disclosure of related party transactions with all other related parties. Redeemable Noncontrolling Interest Redeemable Noncontrolling Interest [Table Text Block] Supplemental Cash Flow Information [Abstract] Notional Value Of Foreign Currency Hedge Derivatives [Axis] Notional Value Of Foreign Currency Hedge Derivatives [Axis] Tabular axis presentation of the aggregate notional value of the Company's foreign exchange contracts. Notional Value Of Foreign Currency Hedge Derivatives [Domain] Notional Value Of Foreign Currency Hedge Derivatives [Domain] Tabular domain presentation of the aggregate notional value of the Company's foreign exchange contracts. Foreign Currency Balances In Foreign Operations [Member] Foreign Currency Balances In Foreign Operations [Member] Aggregate notional value of foreign exchange contracts related to foreign currency balances. Future Production Costs [Member] Future Production Costs [Member] Future Production Costs [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Level 2 Fair Value, Inputs, Level 2 [Member] Derivative, Fair Value, Net Derivative, Fair Value, Net Derivative, Notional Amount Derivative, Notional Amount Cash paid for interest Interest Paid, Excluding Capitalized Interest, Operating Activities Cash paid for income taxes Income Taxes Paid Property and Equipment (Table) Property, Plant and Equipment [Table Text Block] Minimum [Member] Maximum [Member] Accounting Standards Update 2016-16 Accounting Standards Update 2016-16 [Member] Accounting Standards Update 2016-15 [Member] Accounting Standards Update 2016-15 [Member] Accounting Standards Update 2016-01 [Member] Accounting Standards Update 2016-01 [Member] Accounting Standards Update 2017-07 [Member] Accounting Standards Update 2017-07 [Member] Number of Countries in which Entity Operates Number of Countries in which Entity Operates Number of Reportable Segments Number of Reportable Segments Cumulative Effect of New Accounting Principle in Period of Adoption Cumulative Effect of New Accounting Principle in Period of Adoption Contract with Customer, Right to Recover Product, Current Contract with Customer, Right to Recover Product, Current Amortization Period of Deferred Tax Assets Amortization Period of Deferred Tax Assets Amortization period of deferred tax assets relating to intra-entity transfers of assets upon adoption of ASU 2016-16. Accumulated Other Comprehensive Income (Loss), Equity Securities, Available-for-sale, Adjustment, after Tax Accumulated Other Comprehensive Income (Loss), Equity Securities, Available-for-sale, Adjustment, after Tax Accumulated unrealized gain (loss), after tax, on investment in equity security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Net Cash Provided by (Used in) Operating Activities Net Cash Provided by (Used in) Operating Activities Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Title of Individual [Axis] Title of Individual [Axis] Title of Individual [Domain] Title of Individual [Domain] Director Director [Member] Award Type [Axis] Award Type [Axis] Award Type [Domain] Award Type [Domain] Employee Stock Option Restricted Stock Units (RSUs) Restricted Stock Units (RSUs) [Member] Performance Shares Performance Shares [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Expiration period Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period Award vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Measurement period shared based compensation arrangement by share based payment award, measurement period shared based compensation arrangement by share based payment award, measurement period Minimum Percentage of Target Award Shares Award Min Percentage The minimum percentage of target shares an executive is entitled to receive at the end of an applicable measurement period. Maximum Percentage of Target Award Shares Award Max Percentage The maximum percentage of target shares an executive is entitled to receive at the end of an applicable measurement period. Terms of Award Share-based Compensation Arrangement by Share-based Payment Award, Terms of Award Restructuring Reserves Period Expense Future equity awards authorized under LTMIP Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Stock Options [Abstract] -- None. No documentation exists for this element. -- Weighted average remaining contractual life of stock options outstanding Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Weighted average remaining contractual life of stock options exercisable Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Unrecognized compensation costs related to unvested stock options Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Weighted average period of unrecognized compensation recognition related to unvested stock options Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Other Equity Based Awards [Abstract] -- None. No documentation exists for this element. -- Weighted average remaining contractual life of unvested share units Share Based Compensation Other Than Options Unvested Weighted Average Remaining Contractual Life The weighted-average period between the balance-sheet date and forfeiture date for unvested share units, which may be expressed in a decimal value for number of years. Aggregate intrinsic value of unvested share units Share-based Compensation Arrangement by Share-based Payment Award, Equity Instrument Other than Option, Nonvested, Intrinsic Value Fair value of share units vested Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value Unrecognized compensation costs related to share units Employee Service Share Based Compensation Unrecognized Compensation Costs On Nonvested Other Than Options As of the latest balance-sheet date presented, the total compensation cost related to outstanding, nonvested nonstock option awards not yet recognized (will be charged against earnings as services are performed or other vesting criteria are met). Weighted average period of unrecognized compensation recognition related to share units Employee Service Share Based Compensation Unrecognized Compensation Costs On Nonvested Other Than Options Weighted Average Period Of Recognition The weighted average period over which unrecognized nonstock option awards costs are expected to be reported. Supplemental Cash Flow Cash Flow, Supplemental Disclosures [Text Block] Equity Based Compensation Share-based Payment Arrangement [Text Block] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] PlutoTV [Domain] PlutoTV [Domain] PlutoTV [Domain] WhoSay, VidCon, Awesomeness TV [Member] WhoSay, VidCon, Awesomeness TV [Member] [Member] WhoSay Inc., VidCon LLC, Awesomeness TV Holdings, LLC [Member] Telefe [Member] Telefe [Member] Telefe Business Acquisition [Line Items] Business Acquisition [Line Items] Marketable Securities Marketable Securities Payments to Acquire Businesses, Net of Cash Acquired Payments to Acquire Businesses, Net of Cash Acquired Business Combination, Separately Recognized Transactions, Expenses and Losses Recognized Business Combination, Separately Recognized Transactions, Expenses and Losses Recognized Finite-Lived Intangible Asset, Useful Life Finite-Lived Intangible Asset, Useful Life Consolidated Statements of Earnings Other Related Parties Consolidated Statements Of Earnings Tables [Abstract] -- None. No documentation exists for this element. -- Revenues Revenue from Related Parties Operating expenses Related Party Transaction, Expenses from Transactions with Related Party Selling, general and administrative Related Party Transaction, Other Revenues from Transactions with Related Party Consolidated Balance Sheets Other Related Parties Consolidated Balance Sheets Tables [Abstract] -- None. No documentation exists for this element. -- Accounts receivable Due from Related Parties, Current Other assets Due From Related Party Other Assets Current The aggregate amount of other assets at the financial statement date resulting from transactions with related parties. Total due from other related parties Total Due From Related Parties The aggregate amount of receivables and other assets at the financial statement date resulting from transactions with related parties. Accounts payable Due to Related Parties, Current Participants’ share and residuals, current Due To Related Parties Participants Share And Residuals Current Aggregate amount as of the balance sheet date of participants' share and residuals due to related parties; represents the current portion of such liabilities. Program obligations, current Program Rights Obligations, Current Program obligations, noncurrent Program Rights Obligations, Noncurrent Other liabilities Due To Related Parties Other Liabilities Aggregate amount as of the balance sheet date of other liabilities resulting from transactions with related parties; represents the current and noncurrent portion of such liabilities. Total due to other related parties Due to Related Parties Other comprehensive income/(loss), net of tax: Other Comprehensive Income (Loss), Net of Tax [Abstract] Foreign currency translation adjustments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Defined benefit pension plans Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax Cash flow hedges Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax Available-for-sale securities Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, after Tax Other comprehensive income/(loss) (Viacom and noncontrolling interests) Comprehensive income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Less: Comprehensive income attributable to noncontrolling interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Comprehensive income attributable to Viacom Comprehensive Income (Loss), Net of Tax, Attributable to Parent Income Statement [Abstract] Expenses: Costs and Expenses [Abstract] Operating Cost of Goods and Services Sold Selling, general and administrative Selling, General and Administrative Expense Total expenses Other items, net Earnings from continuing operations before provision for income taxes Provision for income taxes Net earnings from continuing operations Discontinued operations, net of tax Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest Net earnings attributable to noncontrolling interests Net Income (Loss) Attributable to Noncontrolling Interest Net earnings attributable to Viacom Amounts attributable to Viacom: Income Amounts Attributable to Parent, Disclosures [Abstract] Discontinued operations, net of tax Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent Basic earnings per share attributable to Viacom: Earnings Per Share, Basic [Abstract] Discontinued operations (in usd per share) Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share Net earnings (in usd per share) Diluted earnings per share attributable to Viacom: Earnings Per Share, Diluted [Abstract] Discontinued operations (in usd per share) Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share Net earnings (in usd per share) Weighted average number of common shares outstanding: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Basic (shares) Weighted Average Number of Shares Outstanding, Basic Diluted (shares) Weighted Average Number of Shares Outstanding, Diluted Debt Schedule of Debt [Table Text Block] NAI NAI [Member] -- None. No documentation exists for this element. -- Ownership Percent Of Class A Stock By Controlling Stockholder OwnershipPercentOfClassAStockByControllingStockholder Percent of Viacom Inc. Class A Common Stock owned by NAI as of the financial statement date Ownership Percent Of Class A And Class B Stock By Controlling Stockholder OwnershipPercentOfClassAAndClassBStockByControllingStockholder Percent of Viacom Inc. Class A and Class B Common Stock, on a combined basis, owned by NAI as of the financial statement date Percentage Of Voting Interest Controlled By The Chairman Of The Controlling Stockholder Entity Percentage Of Voting Interest Controlled By The Chairman Of The Controlling Stockholder Entity Percentage of voting interest controlled by the chairman of the controlling stockholder entity Percentage Of Voting Interest Controlled By Non-Chairman Member Of The Controlling Stockholder Entity Percentage Of Voting Interest Controlled By Non-Chairman Member Of The Controlling Stockholder Entity Percentage Of Voting Interest Controlled By Non-Chairman Member Of The Controlling Stockholder Entity Revenue from Related Parties Quarterly Financial Information Disclosure (Narrative) [Abstract] Quarterly Financial Information Disclosure (Narrative) [Abstract] Condensed Financial Statements [Table] Condensed Financial Statements [Table] Equity Investees By Component [Axis] Equity Investees By Component [Axis] Listing of company equity investees Equity Investee [Domain] Equity Investee [Domain] -- None. No documentation exists for this element. -- Viacom18 Viacom18 [Member] Viacom18 [Member] Employee Severance Quarterly Financial Information Disclosure (Narrative) [Line Items] Condensed Financial Statements, Captions [Line Items] Restructuring and Other Corporate Matters Expense, Net of Tax Restructuring and Other Corporate Matters Expense, Net of Tax Restructuring and Other Corporate Matters Expense, Net of Tax Programming Inventory Restructure, Net of Tax Programming Inventory Restructure, Net of Tax Programming Inventory Restructure, Net of Tax Gain (Loss) on Extinguishment of Debt, Net of Tax Extinguishment of Debt, Gain (Loss), Net of Tax Marketable Securities, Gain (Loss) Marketable Securities, Gain (Loss) Marketable Securities, Gain (Loss), Net of Tax Marketable Securities, Gain (Loss), Net of Tax Marketable Securities, Gain (Loss), Net of Tax Gain on sale of equity method investment Equity Method Investment, Ownership Percentage Equity Method Investment, Ownership Percentage Cost-method Investments, Other than Temporary Impairment Cost-method Investments, Other than Temporary Impairment Cost-method Investments, Other than Temporary Impairment, Net of Tax Cost-method Investments, Other than Temporary Impairment, Net of Tax This item represents an other than temporary decline in value that has been recognized against an investment accounted for under the cost method of accounting (net of tax). The excess of the carrying amount over the fair value of the investment represents the amount of the write down which is or was reflected in earnings. The written down value is a new cost basis with the adjusted value of the investment becoming its new carrying value. Evidence of a loss in value might include, but would not necessarily be limited to, absence of an ability to recover the carrying amount of the investment or inability of the investee to sustain an earnings capacity which would justify the carrying amount of the investment. Schedule of Multiemployer Plans [Table] Schedule of Multiemployer Plans [Table] Multiemployer Plan Type [Axis] Multiemployer Plan Type [Axis] Multiemployer Plans Type [Domain] Multiemployer Plans Type [Domain] Multiemployer Plans, Pension Multiemployer Plans, Pension [Member] Multiemployer Plans, Postretirement Benefit Multiemployer Plans, Postretirement Benefit [Member] Multiemployer Plans [Line Items] Multiemployer Plans [Line Items] Multiemployer Plan, Contributions by Employer Multiemployer Plan, Contributions by Employer Number Of Listings On Form 5500 Number Of Listings On Form 5500 Number Of Listings On Form 5500 Number Of Green Filed Zone Statuses Number Of Green Filed Zone Statuses Number Of Green Filed Zone Statuses Retirement Plan Type [Axis] Retirement Plan Type [Axis] Retirement Plan Type [Domain] Retirement Plan Type [Domain] Retirement Plan Sponsor Location [Axis] Retirement Plan Sponsor Location [Axis] Retirement Plan Sponsor Location [Domain] Retirement Plan Sponsor Location [Domain] Retirement Plan Tax Status [Axis] Retirement Plan Tax Status [Axis] Retirement Plan Tax Status [Domain] Retirement Plan Tax Status [Domain] Retirement Plan Name [Axis] Retirement Plan Name [Axis] Retirement Plan Name [Domain] Retirement Plan Name [Domain] Equity Securities [Member] Debt Securities [Member] Cash and Cash Equivalents [Member] Investment Objective [Axis] Investment Objective [Axis] Investment Objective [Domain] Investment Objective [Domain] Related Party Transaction [Axis] Related Party Transaction [Axis] Related Party Transaction [Domain] Related Party Transaction [Domain] Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage Unrecognized actuarial loss Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax Unrecognized actuarial loss, next fiscal year Defined Benefit Plan, Expected Amortization of Gain (Loss), Next Fiscal Year Weighted Average Number of Common Shares Outstanding and Anti-Dilutive Common Shares Common Shares Outstanding And Anti Dilutive Common Shares Disclosure Table [Table Text Block] Table of computation of the common shares outstanding utilized in determining basic and diluted earnings per common share and anti-dilutive common shares. Receivables Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets Prepaid and other assets Goodwill, Fair Value Disclosure Goodwill Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill Intangible assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment Other assets, noncurrent Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Assets Assets acquired Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets Accounts payable Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities Accrued expenses Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other Other liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities Liabilities assumed Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities Purchase Price Allocation Business Combination, Recognized Total Purchase Price Allocation The total purchase price allocation as of the acquisition date. Options Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Outstanding at the beginning of the period Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Granted Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures Exercised Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Forfeited or expired Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period Outstanding at the end of the period Exercisable at the end of the period Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable The number of shares into which fully or partially vested stock options outstanding as of the balance-sheet date can be currently converted under the option plan at the weighted-average price. Weighted average exercise price Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Outstanding at the beginning of the period Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Granted Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Exercised Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Forfeited or expired Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price Outstanding at the end of the period Exercisable at the end of the period Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Future minimum sublease income Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals Interest included in future capital lease payments Capital Leases, Future Minimum Payments, Interest Included in Payments Rent expense Operating Leases, Rent Expense, Net Recorded liability for lease indemnifications Liability Related To Indemnification Obligations Aggregate liability recorded as of the balance sheet date related to indemnification obligations with respect to leases associated with previously discontinued operations. Outstanding letters of credit Letters of Credit Outstanding, Amount International International [Member] Percentage of European revenues generated in the United Kingdom and Germany. United Kingdom And Germany United Kingdom And Germany [Member] -- None. No documentation exists for this element. -- Percentage Of Total Consolidated Revenues Percentage Of Total Consolidated Revenues Revenues generated from international markets as a percentage of consolidated revenues. Percentage of Total EMEA Revenues Percentage Of Total EMEA Revenues The percentage of total consolidated revenues in Europe, the Middle East, and Asia. United States Income (Loss) from Continuing Operations before Income Taxes, Domestic International Income (Loss) from Continuing Operations before Income Taxes, Foreign Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Recognized actuarial loss Defined Benefit Plan, Amortization of Gain (Loss) Net periodic benefit costs Media Networks Media Networks Segment [Member] -- None. No documentation exists for this element. -- Filmed Entertainment Filmed Entertainment Segment [Member] -- None. No documentation exists for this element. -- Restructuring Reserve, Beginning Balance Accruals RestructuringNetAccrual Amount of expenses associated with exit or disposal activities pursuant to an authorized plan incurred in the period, net of accrual adjustments to previously accrued restructuring liabilities. Severance payments Payments for Restructuring Restructuring Reserve, Ending Balance Restructuring Reserve Rollforward Restructuring Reserve [Roll Forward] Weighted-average assumptions - benefit obligations Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract] Discount rate Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate Weighted-average assumptions - net periodic costs Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract] Discount rate Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate Expected long-term return on plan assets Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets Defined Benefit Plan Effect Of Twenty-Five Basis Point Change On Accumulated Benefit Obligation Defined Benefit Plan Effect Of Twenty-Five Basis Point Of Discount Rate Change On Accumulated Benefit Obligation Estimated impact of a 25 basis point change in the discount rate on the accumulated benefit obligation Defined Benefit Plan Effect Of Twenty Five Basis Point Of Discount Rate Or Expected Rate of Return On Plan Assets Defined Benefit Plan Effect Of Twenty Five Basis Point Of Discount Rate Or Expected Rate of Return On Plan Assets Impact of a 25 basis point change in the discount rate or expected rate of return on plan assets on the net periodic benefit cost. Cover page. Entities [Table] Entities [Table] Entity Information [Line Items] Entity Information [Line Items] Document Type Document Type Document Annual Report Document Annual Report Document Period End Date Document Period End Date Document Transition Report Document Transition Report Entity File Number Entity File Number Entity Registrant Name Entity Registrant Name Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Entity Tax Identification Number Entity Tax Identification Number Entity Address, Address Line One Entity Address, Address Line One Entity Address, City or Town Entity Address, City or Town Entity Address, State or Province Entity Address, State or Province Entity Address, Postal Zip Code Entity Address, Postal Zip Code City Area Code City Area Code Local Phone Number Local Phone Number Title of 12(b) Security Title of 12(b) Security Trading Symbol Trading Symbol Security Exchange Name Security Exchange Name Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Voluntary Filers Entity Current Reporting Status Entity Current Reporting Status Entity Interactive Data Current Entity Interactive Data Current Entity Filer Category Entity Filer Category Entity Small Business Entity Small Business Entity Emerging Growth Company Entity Emerging Growth Company Entity Shell Company Entity Shell Company Entity Public Float Entity Public Float Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Documents Incorporated by Reference Documents Incorporated by Reference [Text Block] Current Fiscal Year End Date Current Fiscal Year End Date Entity Central Index Key Entity Central Index Key Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Amendment Flag Amendment Flag Number of shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Unvested at the beginning of the period Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Granted Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Vested Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Forfeited Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Unvested at the end of the period Weighted average grant date fair value Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Unvested at the beginning of the period Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Granted Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Vested Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Forfeited Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Unvested at the end of the period Performance-based share units included In Grant Activity Performance-Based Share Units Included In Grant Activity Amount of performance-based share units granted at target during the period. Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] Fair value of plan assets, beginning of period Defined Benefit Plan, Plan Assets, Amount Actual return on plan assets Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss) Employer contributions Defined Benefit Plan, Plan Assets, Contributions by Employer Benefits paid Defined Benefit Plan, Plan Assets, Benefits Paid Fair value of plan assets, end of period Contractual Obligations Contractual Obligation, Fiscal Year Maturity [Table Text Block] Proceeds from stock option exercises Proceeds from Stock Options Exercised Intrinsic value Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value Excess tax benefit/(shortfall) EmployeeServiceShareBasedCompensationTaxEffectFromExerciseOfStockOptions Employee Service Share Based Compensation Tax Benefit (Shortfall) From Exercise Of Stock Options Percentage of acquired business recorded at fair value Percentage of acquired business recorded at fair value Percentage of acquired business recorded at fair value. Reserve for sales returns and allowances Allowance For Sales Returns And Allowances A valuation allowance for expected sales returns. Allowance for doubtful accounts Accounts Receivable, Allowance for Credit Loss, Current Advertising expense incurred by the Company Advertising Expense Estimated number of years film inventory earned Estimated number of years film inventory earned Estimated number of years from the date of a film's initial theatrical release that ultimate revenues are earned. Estimate in years of ultimate revenue of acquired film library Estimate in years of ultimate revenue of acquired film library Acquired film library estimated ultimate revenues period in years from the date of acquisition. Number of years film development costs expensed Number of years film development costs expensed Film development costs that have not been set for production are expensed within a certain number of years unless they are abandoned earlier. Foreign currency translation adjustments Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax Defined benefit pension plans Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax Cash flow hedges Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax Available for sale securities AOCI, Debt Securities, Available-for-sale, Adjustment, after Tax Total Goodwill Schedule of Goodwill [Table Text Block] Intangibles Schedule of Indefinite-Lived Intangible Assets [Table Text Block] Amortization of Intangibles Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Capital expenditures Payments to Acquire Productive Assets Variable Interest Entities [Axis] Variable Interest Entities [Axis] Variable Interest Entity, Classification [Domain] Variable Interest Entity, Classification [Domain] Variable Interest Entity, Primary Beneficiary [Member] Variable Interest Entity, Primary Beneficiary [Member] Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 1 [Member] Operating and Broadcast Rights Operating and Broadcast Rights [Member] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] EPIX EPIX [Member] EPIX [Member] Investments [Line Items] Investments Investments Marketable Securities, Gain (Loss) Equity Securities without Readily Determinable Fair Value, Amount Equity Securities without Readily Determinable Fair Value, Amount Value of equity method investments Equity Method Investments Equity interest in investees Proceeds from sale of equity method investment Proceeds from Sale of Equity Method Investments Transaction costs associated with disposition of equity method investment Transaction Costs Disposal Of Equity Method Investment Transaction costs associated with sale or disposal of an equity method investment. Proceeds from Equity Method Investment, Distribution Proceeds from Equity Method Investment, Distribution Variable Interest Entity, Consolidated, Carrying Amount, Assets VIE, Asset carrying value VIE, Asset carrying value Liabilities Liabilities Proceeds received from asset sales Proceeds from Sale of Other Assets, Investing Activities Gain on asset sale, NCI portion Gain (Loss) On Disposition Of Assets, Portion Attributable to NonControlling Interest Gain (Loss) On Disposition Of Assets, Portion Attributable to NonControlling Interest Deferred tax assets Deferred Tax Assets, Net, Noncurrent Deferred tax liabilities Amortization of Intangible Assets Amortization of Intangible Assets Revenues by Segment Reconciliation of Revenue from Segments to Consolidated [Table Text Block] Adjusted Operating Income (Loss) Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table Text Block] Depreciation and Amortization and Total Assets Depreciation and Amortization Total Assets [Table Text Block] Depreciation and Amortization Total Assets [Table Text Block] Capital Expenditures Segment Reporting Capital Expenditures Table [Table Text Block] Total expenditures for additions to long-lived assets other than financial instruments, long-term customer relationships of a financial institution, mortgage and other servicing rights, deferred policy acquisition costs, and deferred tax assets of the reportable segment. Must be disclosed if the amount (a) is included in the determination of segment assets reviewed by the chief operating decision maker or (b) is otherwise regularly provided to the chief operating decision maker, even if not included in the determination of segment assets. Revenues by Component Component Reporting Entity Consolidated Revenue [Table Text Block] This element may be used to capture the complete disclosure for the identification, description, and amounts of all significant reconciling items in the reconciliation of total revenues by component to the entity's consolidated revenues. Geographic Information Schedule of Revenue and Long LIved Assets Attributed to Foreign Countries by Geographical Area [Table Text Block] Schedule of Revenue and Long LIved Assets Attributed to Foreign Countries by Geographical Area [Table Text Block] Weighted average number of common shares outstanding, basic Dilutive effect of equity awards Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Weighted average number of common shares outstanding, diluted Anti-dilutive common shares Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Commercial Paper, at Carrying Value Commercial Paper, at Carrying Value ViacomCBS Class A Shares [Member] ViacomCBS Class A Shares [Member] ViacomCBS Class A Shares [Member] ViacomCBS Class B Shares [Member] [Member] ViacomCBS Class B Shares [Member] [Member] ViacomCBS Class B Shares [Member] [Member] Conversion of Stock, Shares Converted Conversion of Stock, Shares Converted Pension and Other Postretirement Benefits Pension and Other Postretirement Benefits Disclosure [Text Block] Statement of Cash Flows [Abstract] OPERATING ACTIVITIES [Abstract] Net Cash Provided by (Used in) Operating Activities [Abstract] Net earnings (Viacom and noncontrolling interests) Discontinued operations, net of tax Reconciling items: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Feature film and program amortization Feature film and program amortization Portion of theatrical and television, and original and acquired programming cost assets (e.g. direct product costs, including acquired costs and production overhead) that have been expensed in the current period. Equity-based compensation Share-based Payment Arrangement, Noncash Expense Gain on marketable securities Increase (Decrease) in Equity Securities, FV-NI Gain on asset sales Gain (Loss) on Disposition of Assets Deferred income taxes Deferred Income Tax Expense (Benefit) Operating assets and liabilities, net of acquisitions: Increase (Decrease) in Operating Capital [Abstract] Receivables Increase (Decrease) in Accounts and Other Receivables Production and programming Inventory, program rights and participations The increase and decrease in inventory, program rights and participation obligations from the last reporting period to the current. Accounts payable and other current liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities Other, net Increase (Decrease) in Other Operating Assets and Liabilities, Net Net cash provided by operating activities INVESTING ACTIVITIES Net Cash Provided by (Used in) Investing Activities [Abstract] Acquisitions and investments, net Acquisitions and investments, net The cash outflow associated with the acquisition of a business and the purchase of or advances to equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20-50% and exercises significant influence, net of cash. Capital expenditures Grantor trust proceeds Increase (Decrease) of Restricted Investments Net cash provided by/(used in) investing activities Net Cash Provided by (Used in) Investing Activities FINANCING ACTIVITIES Net Cash Provided by (Used in) Financing Activities [Abstract] Borrowings Proceeds from Bank Debt Debt repayments Repayments of Bank Debt Dividends paid Payments of Ordinary Dividends, Common Stock Exercise of stock options Other, net Other Financing Activities Net Accumulation of other financing activities of the Company. Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities Effect of exchange rate changes on cash and cash equivalents Effect of Exchange Rate on Cash and Cash Equivalents Net change in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Cash and cash equivalents at beginning of period Cash and cash equivalents at end of period Debt Debt Disclosure [Text Block] 2020 Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months 2021 Finite-Lived Intangible Assets, Amortization Expense, Year Two 2022 Finite-Lived Intangible Assets, Amortization Expense, Year Three 2023 Finite-Lived Intangible Assets, Amortization Expense, Year Four 2024 Finite-Lived Intangible Assets, Amortization Expense, Year Five U.S. federal statutory income tax rate State and local taxes, net of federal benefit Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent Effect of international operations Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Percent Bankruptcy of an investee Bankruptcy of an investee Bankruptcy of an investee Qualified production activities deduction Effective Income Tax Rate Reconciliation, Deduction, Qualified Production Activity, Percent Change in valuation allowance Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent Tax accounting method change Effective Income Tax Rate Reconciliation,Other Reconciling Items, Percent Tax Cuts and Jobs Act enactment Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent Foreign tax credits on distribution of securities Effective Income Tax Rate Reconciliation, Tax Credit, Foreign, Percent All other, net Effective Income Tax Rate Reconciliation, Other Adjustments, Percent Effective tax rate, continuing operations Effective Income Tax Rate Reconciliation, Percent Stockholders' Equity Stockholders' Equity Note Disclosure [Text Block] Filmed Entertainment [Member] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Other Noncurrent Assets [Member] Other Noncurrent Assets [Member] Contract liabilities, noncurrent (included in Other liabilities) [Member] Contract liabilities, noncurrent (included in Other liabilities) [Member] Contract liabilities, noncurrent (included in Other liabilities) [Member] Accounts Receivable, after Allowance for Credit Loss, Noncurrent Accounts Receivable, after Allowance for Credit Loss, Noncurrent Deferred Revenue, Current Contract with Customer, Liability Contract with Customer, Liability Contract with Customer, Liability, Revenue Recognized Contract with Customer, Liability, Revenue Recognized Contract with Customer, Performance Obligation Satisfied in Previous Period Contract with Customer, Performance Obligation Satisfied in Previous Period Revenue, Remaining Performance Obligation, Amount Revenue, Remaining Performance Obligation, Amount Revenue, remaining performance obligation, period Revenue, remaining performance obligation, period Revenue, remaining performance obligation, period - Period when majority of Unsatisfied revenue will be recognized Revenue, remaining performance obligation, period - Period when majority of Unsatisfied revenue will be recognized Revenue, remaining performance obligation, period - Period when majority of Unsatisfied revenue will be recognized Revolving Credit Agreement Revolving Credit Agreement [Member] Amount of the revolving credit agreement. Long-term Line of Credit Long-term Line of Credit Line of Credit Facility, Maximum Borrowing Capacity Line of Credit Facility, Maximum Borrowing Capacity Debt Instrument Margin Rate, Percentage Rate, Range Minimum Debt Instrument Margin Rate Percentage Rate Range Minimum The percentage points added to the reference rate to compute the borrowing rate on the debt instrument - minimum. Debt Instrument Margin Rate, Percentage Rate, Range Maximum Debt Instrument Margin Rate Percentage Rate Range Maximum The percentage points added to the reference rate to compute the borrowing rate on the debt instrument - maximum Line of Credit Facility, Covenant Terms Line of Credit Facility, Covenant Terms Supplemental Cash Flow Information (Tables) Cash Flow Supplemental Disclosures Table [Table Text Block] Table includes other cash inflows or outflows not specifically identified in our statement of cash flows and information with respect to redeemable noncontrolling interests and variable interest entities. Other Comprehensive Income (Loss), Tax, Parenthetical Disclosures [Abstract] Adjustments for Change in Accounting Principle [Axis] Adjustments for Change in Accounting Principle [Axis] Adjustments for Change in Accounting Principle [Domain] Adjustments for Change in Accounting Principle [Domain] Other Comprehensive Income (Loss), Tax Other Comprehensive Income (Loss), Tax Common Stock, Dividends, Per Share, Declared Common Stock, Dividends, Per Share, Declared Senior notes due September 2019, 5.625% Senior Notes Sept 2019 [Member] Senior notes due in Sept 2019 with a discount rate of 5.625%. Senior notes due December 2019, 2.750% Senior Notes Dec 2019 [Member] Senior notes due in December 2019 with a discount rate of 2.750%. Senior notes due March 2021, 4.500% Senior Notes Mar 2021 [Member] Senior notes due March 2021 at discount rate of 4.500%. Senior notes due December 2021, 3.875% Senior Notes Dec 2021 [Member] Senior notes due Dec 2021 at a discount rate of 3.875% Senior notes due June 2022, 3.125% Senior Notes June 2022 [Member] Senior Notes due in June 2022 at a discount rate of 3.125%. Senior notes due March 2023, 3.250% Senior Notes Mar 2023 [Member] Senior notes due in 2023 with a discount rate of 3.250%. Senior notes due September 2023, 4.250% Senior Notes Sep 2023 [Member] Senior notes due in 2023 with a discount rate of 4.250%. Senior notes due April 2024, 3.875% Senior Notes Apr 2024 [Member] Senior Notes Apr 2024 [Member] Senior debentures due December 2034, 4.850% Senior Debentures December 2034 [Member] Senior debentures due in December 2034 with a discount rate of 4.850%. Senior debentures due April 2036, 6.875% Senior Debentures Apr 2036 [Member] Senior debentures due in 2036 with a discount rate of 6.875%. Senior debentures due October 2037, 6.750% Senior Debentures Oct 2037 [Member] Senior debentures due in Oct 2037 with a discount rate of 6.750%. Senior debentures due February 2042, 4.500% Senior Debentures Feb 2042 [Member] Senior debentures due Feb 2042 at discount rate 4.500%. Senior debentures due March 2043, 4.375% Senior Debentures Mar 2043 [Member] Senior debentures due in 2043 with a discount rate of 4.375%. Senior debentures due June 2043, 4.875% Senior Debentures June 2043 [Member] Senior debentures due June 2043 with a discount rate of 4.875%. Senior debentures due September 2043, 5.850% Senior Debentures Sep 2043 [Member] Senior debentures due in 2043 with a discount rate of 5.850%. Senior debentures due April 2044, 5.250% Senior Debentures Apr 2044 [Member] Senior Debentures Apr 2044 [Member] Senior Notes Senior Notes Junior Subordinated Notes Junior Subordinated Notes Capital lease and other obligations Other Long-term Debt Total debt Long-term Debt Less current portion Noncurrent portion Revenue from External Customers by Products and Services [Table] Revenue from External Customers by Products and Services [Table] Media Networks [Member] Film Entertainment [Member] Advertising Advertising [Member] Affiliate Affiliate Fees Revenue [Member] Affiliate Fees Revenue [Member] Consumer products, recreation and live events [Member] Consumer products, recreation and live events [Member] Consumer products, recreation and live events [Member] Theatrical [Member] Theatrical [Member] Theatrical [Member] Home entertainment [Member] Home entertainment [Member] Home entertainment [Member] License fees [Member] License fees [Member] License fees [Member] Ancillary Ancillary Revenue [Member] Ancillary Revenue [Member] Revenue Reconciling Items Revenue Reconciling Items [Member] Revenue Reconciling Items [Member] Revenue from External Customer [Line Items] Revenue from External Customer [Line Items] Reportable Segments Segment Reporting Disclosure [Text Block] Related Party Transactions Related Party Transactions Disclosure [Text Block] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Level 1 Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Cash and Cash Equivalents Plan Assets Fair Value Cash And Cash Equivalents Fair value of cash and cash equivalents in plan assets. Viacom Class B Common Stock Plan Assets Fair Value Equity Securities Common And Preferred Stock Fair value of common and preferred stock in plan assets. U.S. treasury securities Plan Assets Fair Value Debt Securities U.S. Treasury Securities Includes information about debt securities issued by the United States Department of the Treasury and backed by the United States government. Such securities primarily consist of treasury bills (short-term maturities - one year or less), treasury notes (intermediate term maturities - two to ten years), and treasury bonds (long-term maturities - ten to thirty years). Municipal & government issued bonds Plan Assets Fair Value Debt Securities Municipal and government bonds Bonds or similar securities issued by state, city, or local US government or the agencies operated by state, city, or local governments. Debt securities issued by state governments may include bond issuances of US state authorities, including, for example, but not limited to, housing authorities, dormitory authorities, and general obligations while debt securities issued by political subdivisions of US states would include, for example, debt issuances by county, borough, city or municipal governments. Corporate bonds Plan Assets Fair Value Debt Securities Corporate Bonds Includes domestic and foreign issued corporate bonds. Mortgage-backed & asset-backed securities Plan Assets Fair Value Debt Securities Mortgage backed and asset backed securities Debt securities that include US government and financial institution backed mortgages. Fair value of plan assets in the fair value hierarchy Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Plan Assets Diversified equity and credit funds Diversified equity and credit funds Diversified equity and credit funds Equity securities - world funds Plan Assets Fair Value Equity Securities World Funds Fair value of world funds plan assets which reflects common/collective trust funds. Equity securities - emerging markets Plan Assets Fair Value Equity Securities Emerging Market Funds Fair value of plan assets of equity securities emerging market funds which reflects common/collective trust funds. Debt securities - emerging markets Plan Assets Fair Value Debt Securities Emerging Market Funds Fair value of debt securities that include investments in emerging market funds which reflects common/collective trust funds. Debt securities - multi-strategy Plan Assets Fair Value Debt Securities Multi strategy funds Fair value of debt securities that include investments in common/collective trust funds and limited partnerships. Treasury US rate funds (TURF) Treasury US rate funds Treasury US rate funds Total fair value of plan assets