Organization, Consolidation and Presentation of Financial Statements [Abstract] Reclassification of assets Reclassification Of Assets [Table Text Block] Reclassification Of Assets [Table Text Block] Summary Of Accounting Policies [Table] Summary Of Accounting Policies [Table] Summary Of Accounting Policies [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Restaurant VIEs Restaurant [Member] Restaurant [Member] Summary Of Accounting Policies [Line Items] Summary Of Accounting Policies [Line Items] Summary Of Accounting Policies [Line Items] Equity method investment ownership percentage Equity Method Investment, Ownership Percentage Number of consolidated restaurants Number Of Vie Consolidated Restaurants Number of VIE consolidated restaurants. Equity [Abstract] Stockholders Equity [Table] Stockholders Equity [Table] Stockholders Equity [Table] Restaurant Brands International Limited Partnership Restaurant Brands International Limited Partnership [Member] Restaurant Brands International Limited Partnership [Member] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Partnerships Exchangeable Units Partnerships With Exchangeable Units [Member] Partnerships With Exchangeable Units [Member] Stockholders Equity [Line Items] Stockholders Equity [Line Items] Stockholders Equity [Line Items] Partnership exchangeable units economic interest Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest Partnership exchangeable units economic interest, shares Noncontrolling Interest Ownership Of Common Unit Noncontrolling interest ownership of common unit. Exchange of partnership exchangeable units for RBI common shares, shares Stock Issued During Period, Shares, Conversion of Units Revenue from Contract with Customer [Abstract] Change In Contract With Customer Liability [Roll Forward] Change In Contract With Customer Liability [Roll Forward] Change In Contract With Customer Liability [Roll Forward] Beginning balance Contract with Customer, Liability Revenue recognized that was included in the contract liability balance at the beginning of the year Contract with Customer, Liability, Revenue Recognized Increase, excluding amounts recognized as revenue during the period Contract with Customer, Liability, Increase Excluding Amounts Recognized As Revenue During The Period Contract with Customer, Liability, Increase Excluding Amounts Recognized As Revenue During The Period Impact of foreign currency translation Contract with Customer, Liability, Foreign Currency Translation Contract with Customer, Liability, Foreign Currency Translation Ending balance Other Liabilities Disclosure [Abstract] Other Accrued Liabilities and Other Liabilities, net Other Liabilities Disclosure [Text Block] Revenue Recognition, Multiple-deliverable Arrangements [Table] Revenue Recognition, Multiple-deliverable Arrangements [Table] 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] Amounts Under Previous Standards Calculated under Revenue Guidance in Effect before Topic 606 [Member] Total Adjustments Difference between Revenue Guidance in Effect before and after Topic 606 [Member] 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 Accounting Standards Update 2014-09 [Member] Revenue Recognition, Multiple-deliverable Arrangements [Line Items] Revenue Recognition, Multiple-deliverable Arrangements [Line Items] ASSETS Assets [Abstract] Current assets: Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Accounts and notes receivable, net Accounts, Notes, Loans and Financing Receivable, Net, Current Inventories, net Inventory, Net Prepaids and other current assets Prepaid Expense and Other Assets, Current Total current assets Assets, Current Property and equipment, net Property, Plant and Equipment, Net Intangible assets, net Intangible Assets, Net (Excluding Goodwill) Goodwill Goodwill Net investment in property leased to franchisees Capital Leases, Lessor Balance Sheet, Net Investment in Direct Financing Leases, Noncurrent Other assets, net Other Assets, Noncurrent Total assets Assets LIABILITIES AND SHAREHOLDERS’ EQUITY Liabilities and Equity [Abstract] Current liabilities: Liabilities, Current [Abstract] Accounts and drafts payable Accounts Payable, Current Other accrued liabilities Other Accrued Liabilities, Current Gift card liability Gift Card Liability, Current Current portion of long term debt and capital leases Long-term Debt and Capital Lease Obligations, Current Total current liabilities Liabilities, Current Term debt, net of current portion Long-term Debt, Excluding Current Maturities Capital leases, net of current portion Capital Lease Obligations, Noncurrent Other liabilities, net Other Liabilities, Noncurrent Deferred income taxes, net Deferred Income Tax Liabilities, Net Total liabilities Liabilities Shareholders’ equity: Stockholders' Equity Attributable to Parent [Abstract] Common shares Common Stock, Value, Issued Retained earnings Retained Earnings (Accumulated Deficit) Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income (Loss), Net of Tax Total Restaurant Brands International Inc. shareholders’ equity Stockholders' Equity Attributable to Parent Noncontrolling interests Stockholders' Equity Attributable to Noncontrolling Interest Total shareholders’ equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Total liabilities and shareholders’ equity Liabilities and Equity Debt Disclosure [Abstract] Line of Credit Facility [Table] Line of Credit Facility [Table] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Revolving credit facility Revolving Credit Facility [Member] Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Amount outstanding under credit facility Letters of Credit Outstanding, Amount Letter of credit sublimit as part of revolving credit facility Line of Credit Facility, Capacity Available for Specific Purpose Other than for Trade Purchases Letters of credit issued against credit facility Long-term Line of Credit Remaining borrowing capacity Line of Credit Facility, Remaining Borrowing Capacity Segment Reporting [Abstract] Segment Reporting Segment Reporting Disclosure [Text Block] Goodwill and Intangible Assets Disclosure [Abstract] Amortization expense on intangible assets Amortization of Intangible Assets Current: Dividend payable Dividends Payable, Current Interest payable Interest Payable, Current Accrued compensation and benefits Employee-related Liabilities, Current Taxes payable Accrued Income Taxes, Current Deferred income Contract With Customer, Deferred Income, Current Contract With Customer, Deferred Income, Current Accrued advertising expenses Accrued Advertising, Current Closed property reserve Accrued Vacant Property Costs Current Accrued costs for closed and vacant properties. Restructuring and other provisions Restructuring Reserve, Current Other Other Liabilities, Current Other accrued liabilities Noncurrent: Liabilities, Noncurrent [Abstract] Derivatives liabilities Derivative Liability, Noncurrent Taxes payable Accrued Income Taxes, Noncurrent Contract liabilities, net Contract with Customer, Liability, Noncurrent Unfavorable leases Below Market Lease, Net Accrued pension Liability, Defined Benefit Plan, Noncurrent Accrued lease straight-lining liability Lease Liability, Noncurrent Lease liability noncurrent. Deferred income Contract With Customer, Deferred Income, Noncurrent Contract With Customer, Deferred Income, Noncurrent Other Other Accrued Liabilities, Noncurrent Other liabilities, net Commitments and Contingencies Disclosure [Abstract] Loss Contingencies [Table] Loss Contingencies [Table] Litigation Status [Axis] Litigation Status [Axis] Litigation Status [Domain] Litigation Status [Domain] Pending litigation Pending Litigation [Member] Loss Contingencies [Line Items] Loss Contingencies [Line Items] Number of plaintiffs Loss Contingency, Number of Plaintiffs Earnings Per Share [Abstract] Basic and Diluted Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Statement of Cash Flows [Abstract] Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Premiums paid and non-cash loss on early extinguishment of debt Gains Losses On Extinguishment Of Debt Noncash Portion Gains losses on extinguishment of debt noncash portion. Amortization of deferred financing costs and debt issuance discount Amortization of Debt Issuance Costs and Discounts (Income) loss from equity method investments Income (Loss) from Equity Method Investments Loss (gain) on remeasurement of foreign denominated transactions Foreign Currency Transaction Gain (Loss), Unrealized Net (gains) losses on derivatives Gain (Loss) on Derivative Instruments, Net, Pretax Share-based compensation expense Share-based Compensation Deferred income taxes Deferred Income Taxes and Tax Credits Other Other Noncash Income (Expense) Changes in current assets and liabilities, excluding acquisitions and dispositions: Increase (Decrease) in Operating Capital [Abstract] Accounts and notes receivable Increase (Decrease) in Accounts and Notes Receivable Inventories and prepaids and other current assets Increase (Decrease) In Inventories Prepaid Expenses And Other Current Assets Increase (Decrease) In Inventories Prepaid Expenses And Other Current Assets Accounts and drafts payable Increase (Decrease) in Accounts Payable Other accrued liabilities and gift card liability Increase Decrease In Other Accrued Liabilities And Gift Card Liability Increase decrease in other accrued liabilities and gift card liability. Other long-term assets and liabilities Increase (Decrease) in Other Noncurrent Assets and Liabilities, Net Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Cash flows from investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Payments for property and equipment Payments to Acquire Property, Plant, and Equipment Net proceeds from disposal of assets, restaurant closures, and refranchisings Payments for (Proceeds from) Productive Assets Net payment for purchase of Popeyes, net of cash acquired Payments to Acquire Businesses, Net of Cash Acquired Return of investment on direct financing leases Proceeds from Leases Held-for-investment Settlement/sale of derivatives, net Payments for (Proceeds from) Derivative Instrument, Investing Activities Other investing activities, net Payments for (Proceeds from) Other Investing Activities Net cash provided by (used for) investing activities Net Cash Provided by (Used in) Investing Activities Cash flows from financing activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Proceeds from issuance of long-term debt Proceeds from Issuance of Long-term Debt Repayments of long-term debt and capital leases Repayments of Long-term Debt Payment of financing costs Payments of Financing Costs Payment of dividends on common and preferred shares and distributions on Partnership exchangeable units Payments of Dividends Payments in connection with redemption of preferred shares Payments for Repurchase of Redeemable Noncontrolling Interest Proceeds from stock option exercises Proceeds from Stock Options Exercised Other financing activities, net Proceeds from (Payments for) Other Financing Activities Net cash (used for) provided by financing activities Net Cash Provided by (Used in) Financing Activities Effect of exchange rates on cash and cash equivalents Effect of Exchange Rate on Cash and Cash Equivalents Increase (decrease) in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents at beginning of period Cash and cash equivalents at end of period Supplemental cash flow disclosures: Supplemental Cash Flow Information [Abstract] Interest paid Interest Paid, Excluding Capitalized Interest, Operating Activities Income taxes paid Income Taxes Paid Equity Method Investments and Joint Ventures [Abstract] Equity Method Investments Equity Method Investments and Joint Ventures Disclosure [Text Block] Fair value of our variable term debt and senior notes Long-term Debt, Fair Value Principal carrying amount of our variable term debt and senior notes Long-term Debt, Gross Basis Of Presentation [Table] Basis Of Presentation [Table] Basis Of Presentation [Table] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Tim Hortons Tim Hortons [Member] Tim Hortons [Member] Burger King Burger King [Member] Burger King. Popeyes Popeyes [Member] Popeyes. Basis Of Presentation [Line Items] Basis of Presentation [Line Items] Basis of Presentation [Line Items] Number of restaurants in operation Number of Restaurants Number of countries in which company and franchise restaurants operated (more than) Number of Countries in which Entity Operates Percentage of franchised Tim Hortons, Burger King, and Popeyes restaurants Restaurants Owned By Franchisees Percentage Restaurants owned by franchisees percentage. Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosures [Table] Derivative Instruments and Hedging Activities Disclosures [Table] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Interest rate swaps Interest Rate Swap [Member] Cross currency interest rate contract Cross Currency Interest Rate Contract [Member] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Interest expense, net Interest Expense [Member] Trading Activity [Axis] Trading Activity [Axis] Trading Activity, by Type [Domain] Trading Activity, by Type [Domain] Fixed income interest rate Fixed Income Interest Rate [Member] Investment Type [Axis] Investment Type [Axis] Investment [Domain] Investments [Domain] Hedge Funds Hedge Funds [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Maximum Maximum [Member] Derivative Instruments and Hedging Activities Disclosures [Line Items] Derivative Instruments and Hedging Activities Disclosures [Line Items] Notional value Derivative, Notional Amount Net unrealized loss remaining in AOCI Amount Remaining In AOCI To Be Reclassified To Earnings In Future Periods Amount remaining in AOCI to be reclassified to earnings in future periods. Amount of pre-tax losses in AOCI expect to be reclassified into interest expense Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred Cash received on hedge Derivative, Cash Received on Hedge Net unrealized gains as of termination date Change in Unrealized Gain (Loss) on Foreign Currency Fair Value Hedging Instruments Other Income and Expenses [Abstract] Other Operating Expenses (Income), net Other Income and Other Expense Disclosure [Text Block] Statement of Financial Position [Abstract] Allowances for accounts and notes receivable Allowance for Notes, Loans and Financing Receivable, Current Property and equipment, accumulated depreciation and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Common stock, par value (in usd per share) Common Stock, No Par Value Common stock, shares authorized Common Stock, Shares Authorized, Unlimited [Fixed List] Common stock, shares issued Common Stock, Shares, Issued Common stock, shares outstanding Common Stock, Shares, Outstanding Long-Term Debt Long-term Debt [Text Block] Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] Sales Product [Member] Royalties Royalty [Member] Franchise fees and other revenue Franchisor [Member] Revenues Revenue from Contract with Customer, Excluding Assessed Tax Property revenues Operating Leases, Income Statement, Lease Revenue Revenues Revenues Franchise and property revenues Royalty, Property Revenue, and Franchisor [Member] Royalty, Property Revenue, and Franchisor [Member] Revenues: Revenues [Abstract] Sales Revenues Operating costs and expenses: Operating Costs and Expenses [Abstract] Cost of sales Cost of Goods and Services Sold Franchise and property expenses Franchise And Property Costs Costs incurred and are directly related to generating revenues from leased and rented property or equipment and franchises. These costs include amortization of franchise agreements and franchise bad debt expense. Selling, general and administrative expenses Selling, General and Administrative Expense Other operating expenses (income), net Other Operating Income (Expense), Net Total operating costs and expenses Costs and Expenses Income from operations Operating Income (Loss) Interest expense, net Interest Income (Expense), Nonoperating, Net Income before income taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Income tax expense Income Tax Expense (Benefit) Net income Net income attributable to noncontrolling interests Net Income (Loss) Attributable to Noncontrolling Interest Net income attributable to common shareholders Net Income (Loss) Available to Common Stockholders, Basic Earnings per common share: Earnings Per Share, Basic and Diluted [Abstract] Basic (in usd per share) Earnings Per Share, Basic Diluted (in usd per share) Earnings Per Share, Diluted Reconciliation of Revenue from Segments to Consolidated [Table] Reconciliation of Revenue from Segments to Consolidated [Table] Tim Hortons Burger King And Popeyes Brand Tim Hortons Burger King And Popeyes Brand [Member] Tim Hortons Burger King and Popeyes Brand. Segment Reporting, Revenue Reconciling Item [Line Items] Segment Reporting, Revenue Reconciling Item [Line Items] Number of brands Number Of Brand Number of brand. Number of operating segments Number of Operating Segments Number of reportable segments Number of Reportable Segments Change in contract liabilities Contract with Customer, Asset and Liability [Table Text Block] Schedule of estimated revenues expected to be recognized Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block] Disaggregation of total revenues Disaggregation of Revenue [Table Text Block] Schedule of new accounting pronouncements and adjustments Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block] Accounting Changes and Error Corrections [Abstract] New Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Intangible Assets, net and Goodwill Goodwill and Intangible Assets Disclosure [Text Block] Contract liabilities expected to be recognized in Revenue, Remaining Performance Obligation, Amount Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, remaining performance obligation, expected timing of satisfaction, period Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Net losses (gains) on disposal of assets, restaurant closures, and refranchisings Gain (Loss) on Sale of Assets and Asset Impairment Charges Litigation settlements (gains) and reserves, net Litigation Settlement Expense Reserves Litigation settlement expense (reserves). Net losses (gains) on foreign exchange Foreign Currency Transaction Gain (Loss), before Tax Other, net Other Operating Income (Expense), Other, Net Other operating income (expense), other, net. Other operating expenses (income), net Income Statement [Abstract] Statement [Table] Statement [Table] Statement [Line Items] Statement [Line Items] Income from operations Loss on early extinguishment of debt Gain (Loss) on Extinguishment of Debt Preferred share dividends Temporary Equity, Dividends, Adjustment Earnings per common share Weighted average 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 Cash dividends declared per common share (in usd per share) Common Stock, Dividends, Per Share, Declared Subsequent Events [Abstract] Subsequent Event [Table] Subsequent Event [Table] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Scenario, Forecast Scenario, Forecast [Member] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Subsequent Event [Line Items] Subsequent Event [Line Items] Partnership units, exchange notice, number of exchangeable units (in shares) Partnership Units, Exchange Notice, Number Of Exchangeable Units Partnership Units, Exchange Notice, Number Of Exchangeable Units Partners' capital units, treasury units repurchased (in shares) Partners' Capital Account, Units, Treasury Units Purchased Partnership exchangeable units, number converted (in shares) Partners' Capital Account, Units, Converted Cash dividend paid per common share (in usd per share) Common Stock, Dividends, Per Share, Cash Paid Partnership exchangeable unit (in usd per unit) Distribution Made to Limited Partner, Distributions Declared, Per Unit Cash dividend declared by board (in usd per share) New Accounting Pronouncements New Accounting Pronouncements and Changes in Accounting Principles [Text Block] 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] Term Loan Facility (due February 17, 2024) Term Loan Facility due February Seventeen Two thousand and twenty four [Member] Term loan facility due February seventeen two thousand and twenty four. 2017 4.25% Senior Notes (due May 15, 2024) Two Thousand Seventeen Senior Notes Due May Fifteen Two Thousand Twenty Four [Member] Two Thousand Seventeen Senior Notes Due May Fifteen Two Thousand Twenty Four [Member] 2015 4.625% Senior Notes (due January 15, 2022) Two Thousand Fifteen Senior Notes Due January Fifteen Two Thousand Twenty Two [Member] Two Thousand Fifteen Senior Notes Due January Fifteen Two Thousand Twenty Two [Member] 2017 5.00% Senior Notes (due October 15, 2025) Two Thousand Seventeen Senior Notes Due October Fifteen Two Thousand Twenty Five [Member] Two Thousand Seventeen Senior Notes Due October Fifteen Two Thousand Twenty Five [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Term loan facility Secured Debt Senior notes Senior Notes Other Other Long-term Debt Less: unamortized deferred financing costs and deferred issue discount Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net Total debt, net Long-term Debt Less: current maturities of debt Long-term Debt, Current Maturities Total long-term debt Stated interest rate (as a percent) Debt Instrument, Interest Rate, Stated Percentage Schedule of Revenue by Major Customers, by Reporting Segments [Table] Schedule of Revenue by Major Customers, by Reporting Segments [Table] Geographical [Axis] Geographical [Axis] Geographical [Domain] Geographical [Domain] Canada CANADA United States UNITED STATES Other Others [Member] Others. Revenue, Major Customer [Line Items] Revenue, Major Customer [Line Items] Total revenues Summary of Long-Term Debt Schedule of Debt [Table Text Block] Summary of Fair Value Measurement Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block] Schedule of Interest Expense, Net Interest Income and Interest Expense Disclosure [Table Text Block] Revenues by Operating Segment and Country Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas [Table Text Block] Reconciliation of Segment Income to Net Income (Loss) Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table Text Block] Summary of Change in Components of Accumulated Other Comprehensive Income (Loss) ("AOCI") Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Deferred Revenue Arrangement, by Type [Table] Deferred Revenue Arrangement, by Type [Table] Deferred Revenue Arrangement [Line Items] Deferred Revenue Arrangement [Line Items] Net losses on derivatives Other accrued liabilities and gift card liability Increase (Decrease) In Advertising Fund Restricted Assets And Fund Liabilities Increase (Decrease) In Advertising Fund Restricted Assets And Fund Liabilities Shareholders' Equity Stockholders' Equity Note Disclosure [Text Block] New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Table] Accounting Standards Update 2017-12 Accounting Standards Update 2017-12 [Member] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Schedule of Equity Method Investments [Table] Schedule of Equity Method Investments [Table] Consolidated Entities [Axis] Consolidated Entities [Axis] Consolidated Entities [Domain] Consolidated Entities [Domain] Affiliates Affiliated Entity [Member] Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Revenues from affiliates: Other Operating Expenses (Income), net Schedule of Other Operating Cost and Expense, by Component [Table Text Block] MFDA Arrangements MFDA Arrangements [Member] MFDA Arrangements [Member] Gift Cards Gift Cards [Member] Gift Cards [Member] Advertising Funds Advertising Funds [Member] Advertising Funds [Member] Difference between Revenue Guidance in Effect before and after Topic 606 Retained earnings Cumulative Effect of New Accounting Principle in Period of Adoption Shareholders' Equity Other accrued liabilities Accrued Liabilities, Current Franchise fees Interest expense, net Statement of Comprehensive Income [Abstract] Foreign currency translation adjustment Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Net change in fair value of net investment hedges, net of tax of $0.4, $45.4, $(37.5) and $7.3 Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), After Tax Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), After Tax Net change in fair value of cash flow hedges, net of tax of $7.4, $1.4, $(2.7) and $8.2 Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax Amounts reclassified to earnings of cash flow hedges, net of tax of $0.9, $(2.5), $(1.4) and $(6.3) Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax Gain (loss) recognized on defined benefit pension plans, net of tax of $0.0, $0.2, $0.0 and $1.6 Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax Other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax Comprehensive income (loss) Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Comprehensive income (loss) attributable to noncontrolling interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Comprehensive income attributable to preferred shareholders Comprehensive Income Net Of Tax Attributable To Preferred Shareholders Comprehensive income net of tax attributable to preferred shareholders. Comprehensive income (loss) attributable to common shareholders Comprehensive Income Net Of Tax Attributable To Common Shareholders Comprehensive income (loss) net of tax attributable to common shareholders. Numerator: Numerator Basic [Abstract] Numerator Basic [Abstract] Net income attributable to common shareholders - basic Add: Net income attributable to noncontrolling interests Portion Of Net Income Loss Attributable To PEU Noncontrolling Interest The portion of net income loss, after preferred share dividends, attributable to noncontrolling interests represented by Partnership exchangeable units (PEUs). Net income available to common shareholders and noncontrolling interests - diluted Net Income (Loss) Available to Common Stockholders, Diluted Denominator: Denominator [Abstract] Denominator [Abstract] Weighted average common shares - basic (shares) Exchange of noncontrolling interests for common shares Weighted Average Number of Shares Outstanding, Basic and Diluted Effect of other dilutive securities (shares) Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Weighted average common shares - diluted (shares) Basic earnings per share (in usd per share) Diluted earnings per share (in usd per share) Anti-dilutive securities outstanding (shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Derivatives Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] Pensions Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Foreign Currency Translation Accumulated Foreign Currency Adjustment Attributable to Parent [Member] Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] AOCI Attributable to Parent, Net of Tax [Roll Forward] AOCI Attributable to Parent, Net of Tax [Roll Forward] Beginning balances Foreign currency translation adjustment Net change in fair value of derivatives, net of tax Other Comprehensive Income Change In Fair Value Of Derivatives Net Of Tax Other comprehensive income change in fair value of derivatives net of tax. Amounts reclassified to earnings of cash flow hedges, net of tax Pension and post-retirement benefit plans, net of tax Amounts attributable to noncontrolling interests Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest Ending balances Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Operating Segments Operating Segments [Member] Unallocated Management G&A Segment Reconciling Items [Member] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Popeyes Acquisition Popeyes Acquisition [Member] Popeyes acquisition. Adjusted EBITDA Adjusted Earnings Before Interest Tax Depreciation And Amortization Adjusted earnings before interest tax depreciation and amortization. Share-based compensation and non-cash incentive compensation expense Share Based Compensation And Non Cash Incentive Compensation Expense The aggregate amount of share-based compensation and the portion of annual non-cash incentive compensation that eligible employees elected or are expected to elect to receive as common equity in lieu of their cash bonus. PLK Transaction costs Business Combination, Acquisition Related Costs Corporate restructuring and tax advisory fees Business Combination, Integration Related Costs Office centralization and relocation costs Office Centralization And Relocation Costs Office Centralization And Relocation Costs Impact of equity method investments Other operating expenses (income), net EBITDA Earnings Before Interest Tax Depreciation And Amortization Earnings before interest tax depreciation and amortization. Depreciation and amortization Depreciation And Amortization Excluding OIE Depreciation Depreciation and amortization excluding depreciation and amortization included in other (income) expenses, net. Interest expense, net Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Summary of Franchise and Property Revenues Schedule of Related Party Transactions [Table Text Block] Income Tax Disclosure [Abstract] Effective income tax rate Effective Income Tax Rate Reconciliation, Percent Effective income tax rate reconciliation, stock option exercises Effective Income Tax Rate Reconciliation, Share-based Compensation, Excess Tax Benefit, Percent Tax effect on change in fair value of investment hedges Derivatives used in Net Investment Hedge, Tax Expense (Benefit) Tax effect of changes in fair value of cash flow hedges Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax Tax effect on amounts reclassified to earnings of cash flow hedges Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax Tax effect on gain (loss) recognized on defined benefit pension plans Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Other assets, net Other Assets [Member] Investment, Name [Axis] Investment, Name [Axis] Investment, Name [Domain] Investment, Name [Domain] Wendy's Company TIMWEN Partnership Wendy's Company TIMWEN Partnership Wendy's Company TIMWEN Partnership Carrols Restaurant Group, Inc. Carrols Restaurant Group Inc [Member] Carrols Restaurant Group Inc [Member] BK Brasil BK Brasil [Member] BK Brasil [Member] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Equity Method Investee Equity Method Investee [Member] Equity method investments Equity Method Investments Joint-venture interest Cash distributions Proceeds from Equity Method Investment, Distribution Quoted market price Equity Method Investment, Quoted Market Value Contingent rent expense Operating Leases, Rent Expense, Contingent Rentals Accounts receivable from equity method investments Accounts Receivable, Related Parties, Current Increase to carrying value of equity method investment Equity Method Investment, Difference Between Carrying Amount and Underlying Equity Accounts and notes receivable, net of allowance of $17.8 and $16.4, respectively Property and equipment, net of accumulated depreciation and amortization of $716.5 and $623.3, respectively Common shares, no par value; unlimited shares authorized at September 30, 2018 and December 31, 2017; 251,120,351 shares issued and outstanding at September 30, 2018; 243,899,476 shares issued and outstanding at December 31, 2017 Hedging Relationship [Axis] Hedging Relationship [Axis] Hedging Relationship [Domain] Hedging Relationship [Domain] Derivatives designated as cash flow hedges Cash Flow Hedging [Member] Derivatives designated as net investment hedges Net Investment Hedging [Member] Forward-currency contracts Forward Currency Contracts [Member] Forward Currency Contracts [Member] Cross-currency rate swaps Currency Swap [Member] Cost of sales Cost of Sales [Member] Gain or (Loss) Recognized in Other Comprehensive Income (Loss) Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax Gain or (Loss) Recognized in Other Comprehensive Income (Loss) Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), before Reclassification and Tax Gain or (Loss) Reclassified from AOCI into Earnings Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax Gain or (Loss) Recognized in Earnings (Amount Excluded from Effectiveness Testing) Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), Reclassification, before Tax Earnings per Share Earnings Per Share [Text Block] Description of Business and Organization Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block] Income Taxes Income Tax Disclosure [Text Block] Quantitative disclosures of derivative instruments Derivative Instruments, Gain (Loss) [Table Text Block] Summary of fair value measurements Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Schedule of Other Accrued Liabilities (Current) and Other Liabilities (Non-Current), Net Schedule of Accrued Liabilities [Table Text Block] Subsequent Events Subsequent Events [Text Block] Document And Entity Information [Abstract] Document And Entity Information [Abstract] Document Type Document Type Amendment Flag Amendment Flag Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Trading Symbol Trading Symbol Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Emerging Growth Company Entity Emerging Growth Company Entity Small Business Entity Small Business Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Basis of Presentation and Consolidation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Derivative [Table] Derivative [Table] Interest rate Interest Rate Contract [Member] Foreign currency Foreign Currency [Member] Foreign Currency [Member] Prepaids and other current assets Prepaid Expenses and Other Current Assets [Member] Other liabilities, net Other Liabilities [Member] Other accrued liabilities Other Accrued Liabilities [Member] Other accrued liabilities. Derivative [Line Items] Derivative [Line Items] Derivatives assets Derivative Asset, Fair Value, Gross Asset Derivatives liabilities Derivative Liability, Fair Value, Gross Liability Derivative Instruments Derivative Instruments and Hedging Activities Disclosure [Text Block] Schedule of Intangible Assets, Net and Goodwill Schedule of Intangible Assets and Goodwill [Table Text Block] Revenue Recognition Revenue from Contract with Customer [Text Block] Statement of Stockholders' Equity [Abstract] Issued Common Shares Common Stock [Member] Retained Earnings Retained Earnings [Member] Noncontrolling Interest Noncontrolling Interest [Member] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Beginning balances, shares Cumulative effect adjustment Stock option exercises, shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Stock option exercises Stock Issued During Period, Value, Stock Options Exercised Share-based compensation Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Issuance of shares, shares Stock Issued During Period, Shares, New Issues Issuance of shares Stock Issued During Period, Value, New Issues Dividends declared Dividends, Common Stock, Cash Dividend equivalents declared on restricted stock units Dividends, Share-based Compensation, Cash Distributions declared by Partnership on Partnership exchangeable units Distribution Made to Limited Partner, Cash Distributions Declared Exchange of Partnership exchangeable units for RBI common shares Stock Issued During Period, Value, Conversion of Units Restaurant VIE contributions (distributions) Restaurant Variable Interest Entity Contribution Distribution Restaurant variable interest entity distributions. Other comprehensive income (loss) Ending balances, shares Condensed Balance Sheet Statement [Table] Condensed Balance Sheet Statement [Table] Restatement [Axis] Restatement [Axis] Restatement [Domain] Restatement [Domain] As Reported Previously Reported [Member] Reclassification Restatement Adjustment [Member] Condensed Balance Sheet Statements, Captions [Line Items] Condensed Balance Sheet Statements, Captions [Line Items] Advertising fund restricted assets Other Restricted Assets, Current Advertising fund liabilities Accrued Advertising Fund Liabilities Current Accrued Advertising Fund Liabilities Current Finite And Indefinite Lived Intangible Assets [Table] Finite And Indefinite Lived Intangible Assets [Table] Finite And Indefinite 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] Franchise agreements Franchise Rights [Member] Favorable leases Off-Market Favorable Lease [Member] Indefinite-lived Intangible Assets [Axis] Indefinite-lived Intangible Assets [Axis] Indefinite-lived Intangible Assets, Major Class Name [Domain] Indefinite-lived Intangible Assets, Major Class Name [Domain] Trade Names Trade Names [Member] Finite And Indefinite Lived Intangible Assets [Line Items] Finite And Indefinite Lived Intangible Assets [Line Items] Finite And Indefinite Lived Intangible Assets [Line Items] Identifiable assets, Gross Finite-Lived Intangible Assets, Gross Identifiable assets, Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Identifiable assets, Net Finite-Lived Intangible Assets, Net Indefinite lived intangible assets: Indefinite-lived Intangible Assets (Excluding Goodwill) Intangible assets, net Debt Interest Expense, Debt, Excluding Amortization Capital lease obligations Interest Expense, Lessee, Assets under Capital Lease Amortization of deferred financing costs and debt issuance discount Interest income Investment Income, Interest Interest expense, net Gain (loss) reclassified to earnings, net investment hedge