Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Fair value loss on investment Loss on Sale of Investments Share-based payment award, equity instruments other than options, share-based liabilities paid Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Share-Based Liabilities Paid Trading Arrangement: Trading Arrangement [Axis] Maximum Maximum [Member] Exercised/Vested (in dollars per share) Share-Based Compensation Arrangement By Share-Based Payment Award, Equity Instruments Other Than Options, Exercises In Period, Weighted Average Grant Date Fair Value Share-Based Compensation Arrangement By Share-Based Payment Award, Equity Instruments Other Than Options, Exercises In Period, Weighted Average Grant Date Fair Value Statistical Measurement [Domain] Statistical Measurement [Domain] iGaming iGaming [Member] iGaming. Title of 12(b) Security Title of 12(b) Security Subsequent Event Subsequent Event [Member] Net (loss) income attributable to Flutter shareholders – diluted Net Income (Loss) Available to Common Stockholders, Diluted Document Fiscal Year Focus Document Fiscal Year Focus Goods And Service Tax Claim Pending In Respect Of Online Gaming Business Goods And Service Tax Claim Pending In Respect Of Online Gaming Business [Member] Goods and service tax claim pending in respect of online gaming business. Business combination, acquisition-related cost, expense Business Combination, Acquisition-Related Cost, Expense Schedule of Fair Value, Assets, Liabilities And Noncontrolling Interest, Unobservable Input Reconciliation Fair Value, Assets, Liabilities And Noncontrolling Interest, Unobservable Input Reconciliation [Table Text Block] Fair Value, Assets, Liabilities And Noncontrolling Interest, Unobservable Input Reconciliation Adjustment to Compensation, Amount Adjustment to Compensation Amount Change in unrealized gains or losses for the period included in other  comprehensive (loss) income Redeemable Noncontrolling Interest, Assets (Liability), Gain (Loss), OCI Redeemable Noncontrolling Interest, Assets (Liability), Gain (Loss), OCI Financial Instrument [Axis] Financial Instrument [Axis] Number of Units Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Segment Reporting [Abstract] Segment Reporting [Abstract] Restructuring Plan [Axis] Restructuring Plan [Axis] Snai Snai [Member] Snai Ordinary shares (Authorized 300,000,000 shares of €0.09 (September 30, 2026: $0.10; December 31, 2025: $0.11) par value each; issued September 30, 2026: 173,820,519 shares; December 31, 2025: 175,224,066 shares) Common Stock, Value, Issued Trademarks Trademarks [Member] GBP Credit Facility GBP Credit Facility [Member] GBP credit facility. 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Financing related fees not eligible for capitalization Gain (Loss) Financing Related Fees Not Eligible for Capitalization Gain (Loss) Financing Related Fees Not Eligible for Capitalization Dividend distributed to non-controlling interests Temporary Equity, Dividend Distributed to Non-Controlling Interests Temporary Equity, Dividend Distributed to Non-Controlling Interests Total gains or losses for the period: Gains (Losses) For The Period, Fair Value Disclosure [Abstract] Gains (Losses) For The Period, Fair Value Disclosure Other comprehensive income (loss), net of tax: Other Comprehensive Income (Loss), Net of Tax [Abstract] Non-cash interest expense, net Non Cash Interest Expense Net Non-cash interest expense net. Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] 2030 Other Commitment, to be Paid, Year Four Beginning balance Ending balance Redeemable Noncontrolling Interest, Equity, Redemption Value Sports betting open positions Sports Betting Open Position Current Sports betting open position Current. 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Recent Accounting Pronouncements Not Yet Adopted New Accounting Pronouncements, Policy [Policy Text Block] Litigation Case [Axis] Litigation Case [Axis] Euro Senior Secured Notes Euro Senior Secured Notes [Member] Euro Senior Secured Notes Schedule of Segment Reporting Segment Reporting [Table Text Block] Non- controlling interests Noncontrolling Interest [Member] Other comprehensive income (loss) attributable to Flutter shareholders Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Net current period other comprehensive income (loss) (before tax) Other Comprehensive Income (Loss), before Tax Player deposit liability Increase Decrease In Player Deposit Liability Increase decrease in player deposit liability. 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[Member] Other Regions Adoption Date Trading Arrangement Adoption Date Schedule of Other Income (Expense), Net Schedule of Other Nonoperating Income (Expense) [Table Text Block] Counterparty Name [Domain] Counterparty Name [Domain] Dividend distributed to non-controlling interests Dividends, Common Stock, Cash Total Flutter Shareholders’ Equity Equity, Attributable to Parent INTEREST EXPENSE, NET Interest Income and Interest Expense Disclosure [Text Block] 2028 Other Commitment, to be Paid, Year Two Discount For Lack Of Control Based On Fan Duels Equity Ownership And Data Based On Megarstat Studies Discount For Lack Of Control Based On Fan Duels Equity Ownership And Data Based On Megarstat Studies [Member] Discount For Lack Of Control Based On Fan Duels Equity Ownership And Data Based On Megarstat Studies [Member] ASSETS Assets [Abstract] Title Trading Arrangement, Individual Title Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification 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Restricted Stock Restricted Stock [Member] Accumulated other comprehensive loss  Total  AOCI Attributable to Parent [Member] All Individuals All Individuals [Member] SUBSEQUENT EVENTS Subsequent Events [Text Block] Non-cash operating lease expense Operating Lease, Right-of-Use Asset, Periodic Reduction Price Volatility Measurement Input, Price Volatility [Member] Schedule of Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue [Table Text Block] Name Forgone Recovery, Individual Name Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Weighted- Average Fair Value Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Business combination, consideration transferred and preacquisition equity interest in acquiree Business Combination, Consideration Transferred and Preacquisition Equity Interest in Acquiree Betting duty, excise tax, data rights, and racefield fees Betting Duty Data Rights and Product and Race Field Fees Current Betting duty data rights and product and race field fees current. Statement [Line Items] Statement [Line Items] Term Loan B Term Loan B [Member] Term Loan B TOTAL ASSETS Assets Entity [Domain] Entity [Domain] Austria And German Payer Claims Austria And German Payer Claims [Member] Austria And German Payer Claims [Member] Redeemable noncontrolling interest, revenue multiple Redeemable Noncontrolling Interest, Revenue Multiple Redeemable Noncontrolling Interest, Revenue Multiple Net loss attributable to non-controlling interests and redeemable non-controlling interests Income (Loss) from Continuing Operations, Net of Tax, Attributable to Noncontrolling Interest Operating Segments Operating Segments [Member] Schedule of Share-Based Payment Arrangement, Expensed and Capitalized Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]  Equity securities – Investments Equity Securities without Readily Determinable Fair Value, Amount SHARE-BASED COMPENSATION Share-Based Payment Arrangement [Text Block] Other comprehensive income (loss) before reclassifications Other Comprehensive Income (Loss), before Reclassifications, before Tax DESCRIPTION OF BUSINESS Nature of Operations [Text Block] PEO PEO [Member] 2028 Long-Term Debt, Maturity, Year Two Line of credit facility, maximum amount outstanding during period Line of Credit Facility, Maximum Amount Outstanding During Period Share-based compensation expense Total Share-Based Payment Arrangement, Expense Arithmetic Average Arithmetic Average [Member] Repurchase of shares (in shares) Stock Repurchased and Retired During Period, Shares Other non-current liabilities Other Liabilities, Noncurrent Goodwill Goodwill Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Stock options exercised (in shares) Exercised/Vested (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period Granted (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Subsequent Event Type [Domain] Subsequent Event Type [Domain] Income taxes payable Taxes Payable, Current Retained earnings Retained Earnings [Member] Operating lease liabilities – non-current Operating Lease, Liability, Noncurrent Revolving Credit Facility Revolving Credit Facility [Member] Cancelled/Lapsed (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Unrealized gains and losses on available- for- sale debt  securities   AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member] Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Cancelled/Lapsed (in shares) Shares called/lapsed (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures in Period Asset retirement obligation Noncash Asset Retirement Obligation Noncash Asset Retirement Obligation Other interest expense Other Interest Expense Other Interest Income Expense. 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Entity Current Reporting Status Entity Current Reporting Status Net cash (used in) provided by financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Total Shareholder Return Amount Total Shareholder Return Amount Prepaid expenses and other current assets Increase (Decrease) in Prepaid Expense and Other Assets  Financial liabilities measured at fair value: Liabilities, Fair Value Disclosure [Abstract] Cash Flow Hedging Cash Flow Hedging [Member] Term Loan A2 Term Loan A2 [Member] Term Loan A2 Litigation Case [Domain] Litigation Case [Domain] Discount For Lack Of Marketability And Control Discount For Lack Of Marketability And Control [Member] Discount For Lack Of Marketability And Control [Member] Included in earnings Fair Value, Assets and Liabilities Measured on Recurring Basis, Gain (Loss) Included in Earnings Stockholders' Equity Note [Abstract] Stockholders' Equity Note [Abstract] Total gains or losses for the period: Gains (Loss) For The Period, Liabilities, Fair Value Disclosure [Abstract] Gains (Loss) For The Period, Liabilities, Fair Value Disclosure Ownership [Domain] Ownership [Domain] Technology, research and development expenses Technology, research and development expenses Research and Development Expense Adjustments to reconcile net income to net cash from operating activities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] 2029 Long-Term Debt, Maturity, Year Three Bank Overdrafts Bank Overdrafts [Member] Finite lived intangible assets acquired Intangible Asset, Finite-Lived, Acquired Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Share-Based Payment Arrangement [Abstract] Letter Of Guarantee Letter Of Guarantee [Member] Letter Of Guarantee [Member] CASH FLOWS FROM FINANCING ACTIVITIES Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Property and equipment, net Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization Other Service, Other [Member] Financial Instruments [Domain] Financial Instruments [Domain]  Derivative financial assets Derivative Asset USD First Lien Term Loan B due 2032 USD First Lien Term Loan B due 2032 [Member] USD First Lien Term Loan B due 2032 Non-controlling interest Business Combination, Acquisition of Less than 100 Percent, Noncontrolling Interest, Fair Value Intangible Asset, Finite-Lived, Class [Axis] Intangible Asset, Finite-Lived, Class [Axis] Shares issued on exercise of employee share options Stock Issued During Period, Value, Stock Options Exercised Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] GBP Senior Secured Notes due 2031 GBP Senior Secured Notes due 2031 [Member] GBP Senior Secured Notes due 2031 Underlying Securities Award Underlying Securities Amount Net loss attributable to non-controlling interests and redeemable non-controlling interest Net Income (Loss) Attributable to Noncontrolling Interests and Redeemable Noncontrolling Interests Net income loss attributable to non-controlling interests and redeemable non-controlling interests. Leverage ratio Debt Instrument, Covenant, Leverage Ratio Debt Instrument, Covenant, Leverage Ratio Option to acquire ownership percentage Option Indexed To Issuer's Equity, Ownership Percentage To Acquire Option Indexed To Issuer's Equity, Ownership Percentage To Acquire Segment Reporting [Table] Segment Reporting [Table] Non-cash issuance of common stock upon exercise of options Stock Issued Net (loss) income Temporary Equity, Net Income Acquisitions and settlements: Acquisitions and Settlements, Liabilities, Fair Value Disclosure [Abstract] Acquisitions and Settlements, Liabilities, Fair Value Disclosure Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] All Trading Arrangements All Trading Arrangements [Member] Beginning balance Ending balance Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value Change in fair value of derivatives Derivative, Gain (Loss) on Derivative, Net Other Performance Measure, Amount Other Performance Measure, Amount Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Operating loss Operating Income (Loss) Capitalized Development Cost Capitalized Development Cost [Member] Capitalized Development Cost Line of credit facility issuance guarantees Line Of Credit Facility, Issuance Guarantees Line of credit facility issuance guarantees. Asia Pacific Asia Pacific [Member] Current Fiscal Year End Date Current Fiscal Year End Date Foreign exchange (loss) gain on translation of the net assets of foreign currency denominated entities Other Comprehensive Income, Gain (Loss) Due To Translation Of Net Assets Denominated In Foreign Currency, After Adjustments And Tax Other comprehensive income gain loss due to translation of net assets denominated in foreign currency net of tax. 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USD Senior Secured Notes due 2029 USD Senior Secured Notes Due 2029 [Member] USD Senior Secured Notes Due 2029 [Member] Restructuring and other strategic initiative fees Restructuring And Other Strategic Initiative Fees Restructuring and other strategic initiative fees.  Available for sale – Player deposits – Investments Debt Securities, Available-for-Sale, Current CHANGES IN ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) Comprehensive Income (Loss) Note [Text Block] Equity Components [Axis] Equity Components [Axis] Accounts receivable Increase (Decrease) in Accounts Receivable Product and Service [Domain] Product and Service [Domain] Class of Stock [Line Items] Class of Stock [Line Items] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Entity Interactive Data Current Entity Interactive Data Current Net (loss) income attributable to redeemable non-controlling interest Net Income (Loss) Attributable to Noncontrolling Interest Deferred tax liabilities Deferred Income Tax Liabilities, Net Player deposits – cash and cash equivalents Player Deposits Cash and Cash Equivalents The carrying amount of player funds as of balance sheet date, classified as current. Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Adjustment of redeemable non-controlling interest to redemption value Noncontrolling Interest, Change in Redemption Value Entity Small Business Entity Small Business Termination Date Trading Arrangement Termination Date Other Commitments [Axis] Other Commitments [Axis] Southern Europe and Africa Southern Europe And Africa [Member] Southern Europe And Africa Accounts payable Increase (Decrease) in Accounts Payable, Trade Subsequent Events [Abstract] Subsequent Events [Abstract] Settlements Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements Intangible assets, net Business Combination, Recognized Asset Acquired, Identifiable Intangible Asset, Finite-Lived Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Other current liabilities Total other current liabilities Other Liabilities, Current Other non-current assets Other Assets, Noncurrent Value-added tax and goods and services tax Inventory Current Inventory current. Document Type Document Type Acquisitions, net of cash acquired Payments to Acquire Businesses, Net of Cash Acquired Derivative financial assets Derivative Asset, Current Accrued expenses Accrued Liabilities, Current Loss on extinguishment Gain (Loss) on Extinguishment of Debt Fair Value as of Grant Date Award Grant Date Fair Value SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Significant Accounting Policies [Text Block] Brazil BRAZIL CASH, CASH EQUIVALENTS AND RESTRICTED CASH comprise of: Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Including Discontinued Operation [Abstract] Increase (Decrease) in Temporary Equity [Roll Forward] Increase (Decrease) in Temporary Equity [Roll Forward] Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Arrangement Duration Trading Arrangement Duration Subsequent Event [Line Items] Subsequent Event [Line Items] Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Local Phone Number Local Phone Number Contract with customer, liability, noncurrent Contract with Customer, Liability, Noncurrent Settlement of liability-classified share-based awards in equity (in shares) Settlement Of Liability-Classified Share-Based Awards In Equity, Shares Settlement Of Liability-Classified Share-Based Awards In Equity, Shares Consolidation Items [Axis] Consolidation Items [Axis] Player deposits – investments Player Deposits, Investments Player deposits investments. Entity Address, Postal Zip Code Entity Address, Postal Zip Code Entity Registrant Name Entity Registrant Name Net Investment Hedging Net Investment Hedging [Member] Business combination, preacquisition contingency, settlement, amount Business Combination, Preacquisition Contingency, Settlement, Amount Depreciation and amortization excluding amortization of acquired intangibles Depreciation, Depletion And Amortization, Adjusted Depreciation, Depletion And Amortization, Adjusted Loss before income taxes Loss before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Number of countries in which entity operates Number of Countries in which Entity Operates Fair Value, Asset (Liability), Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Fair Value, Asset (Liability), Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Warrants and rights outstanding, term Warrants and Rights Outstanding, Term Adjustment of redeemable non-controlling interest to redemption value Adjustment of redeemable non-controlling interest at redemption at fair value Temporary Equity, Accretion to Redemption Value, Adjustment COMMITMENTS AND CONTINGENCIES (Note 17) Commitments and Contingencies Gain (loss) on foreign currency fair value hedge derivatives Gain (Loss) on Foreign Currency Fair Value Hedge Derivatives Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Warrants and rights measurement input Warrants and Rights Outstanding, Measurement Input Equity, Attributable to Noncontrolling Interest [Roll Forward] Equity, Attributable to Noncontrolling Interest [Roll Forward] Income Tax Contingency [Table] Income Tax Contingency [Table] Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Redeemable noncontrolling interest, equity to debt, ratio Redeemable Noncontrolling Interest, Equity To Debt, Ratio Redeemable Noncontrolling Interest, Equity To Debt, Ratio Executive Category: Executive Category [Axis] Tax effect Other Comprehensive Income (Loss), Tax His Majesty's Revenue and Customs (HMRC) His Majesty's Revenue and Customs (HMRC) [Member] Purchase of long lived assets with accrued expense - financing Capital Expenditures Incurred but Not yet Paid, Financing Activities Capital Expenditures Incurred but Not yet Paid, Financing Activities Counterparty Name [Axis] Counterparty Name [Axis] LIABILITIES, REDEEMABLE NON-CONTROLLING INTERESTS AND SHAREHOLDERS’ EQUITY Liabilities and Equity [Abstract] Other Commitments [Table] Other Commitments [Table] Intangible Asset, Finite-Lived, Class [Domain] Intangible Asset, Finite-Lived, Class [Domain] Australia AUSTRALIA Term Loan A Term Loan A And Revolving Credit Facility [Member] Term Loan A And Revolving Credit Facility Acquisition of NSX Acquisition of redeemable non-controlling interest Temporary Equity, Increase During The Period Due To Business Combination Temporary equity increase during the period due to business combination. Beginning balance Ending balance Temporary Equity, Carrying Amount, Attributable to Parent Award Type [Domain] Award Type [Domain] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount FAIR VALUE MEASUREMENTS Fair Value Disclosures [Text Block]   Level 3   Fair Value, Inputs, Level 3 [Member] SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION: Supplemental Cash Flow Information [Abstract] Fair value of cash flow hedges transferred to the income statement Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax PEO Name PEO Name Geographical [Axis] Geographical [Axis] Gains and loss on cash  flow hedges Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] Income tax paid (net of refunds) Income Tax Paid, before Refund Received Investment in equity Excludes Equity Securities, FV-NI and without Readily Determinable Fair Value Payment of contingent consideration Payment for Contingent Consideration Liability, Financing Activities Prepayments and accrued income Prepayments Prepayments and accrued income. Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Entity Tax Identification Number Entity Tax Identification Number Fair Value, Assets (Liabilities) Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Fair Value, Assets (Liabilities) Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Fair Value, Assets (Liabilities) Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation Legal Entity [Axis] Legal Entity [Axis] Interest and amortization of debt discount and expense on long-term debt, bank guarantees Interest Expense, Debt Cash settlement of derivatives designated in net investment hedge Payments for (Proceeds from) Derivative Instrument, Investing Activities Carrying amount Hedged Liability, Fair Value Hedge Effective portion of changes in fair value of cash flow hedges Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax Liability Class [Axis] Liability Class [Axis] Other Commitments [Line Items] Other Commitments [Line Items] Thereafter Long-Term Debt, Maturity, After Year Four Long-Term Debt, Maturity, After Year Four Ireland IRELAND Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Non-NEOs Non-NEOs [Member] Cash and cash equivalents – restricted Cash and cash equivalents - restricted Restricted Cash and Cash Equivalent, Current Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] Number of positions eliminated Restructuring and Related Cost, Number of Positions Eliminated Total comprehensive (loss) income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Debt Instrument [Axis] Debt Instrument [Axis] Subsequent Event [Table] Subsequent Event [Table] Cash payment Payments to Acquire Businesses, Gross Share-based compensation – equity classified Share-Based Payment Arrangement, Noncash Expense Settlements Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset (Liabilities), Settlements Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset (Liabilities), Settlements Italy ITALY Income Tax Authority, Name [Domain] Income Tax Authority, Name [Domain] Schedule of Group's Debt Comprised Schedule of Debt [Table Text Block] Acquisition of redeemable non-controlling interests Payments for Repurchase of Redeemable Noncontrolling Interest Transaction costs with third parties from issuance of long-term debt Repayments of Transaction Costs With Third Parties From Issuance of Long Term Debt Repayments of Transaction Costs With Third Parties From Issuance of Long Term Debt 2027 Long-Term Debt, Maturity, Year One Schedule of the Fair Value of Derivatives Assets and Liabilities Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Basic (in USD per share) Earnings Per Share, Basic USD denominated debt USD-denominated debt [Member] USD-denominated debt Measurement Input Type [Axis] Measurement Input Type [Axis] Adjustment of redeemable non-controlling interest to fair value Temporary Equity, Accretion to Redemption Value Contract liability, beginning and end of period Contract with Customer, Liability, Current Repurchase of ordinary shares and taxes withheld and paid on employee share awards Payments for Repurchase of Common Stock TOTAL CURRENT ASSETS Assets, Current Statistical Measurement [Axis] Statistical Measurement [Axis] Insider Trading Arrangements [Line Items] Foreign exchange gain (loss) on net investment hedges Other Comprehensive 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Liabilities and Equity Interest income Interest Income, Other Employee Stock Option Share-Based Payment Arrangement, Option [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Amounts reclassified from accumulated other comprehensive income (loss) Amounts reclassified from accumulated other comprehensive income (loss) Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax Non-controlling interests Equity, Attributable to Noncontrolling Interest Euro denominated debt Euro-denominated debt [Member] Euro-denominated debt Segments [Axis] Segments [Axis] Other liabilities Increase (Decrease) in Other Operating Liabilities Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Plan Name [Axis] Plan Name [Axis] Restructuring and integration costs Restructuring Charges Tabular List, Table Tabular List [Table Text Block] Value-added tax and goods and services tax Sales and Excise Tax Payable, Current Purchases of intangible assets Payments to Acquire Intangible Assets Other income, net Other income, net Total other income, net Other Nonoperating Income (Expense) LONG-TERM DEBT Long-Term Debt [Text Block] Gain (loss) on disposals Gain (Loss) On Disposal Of Property Plant And Equipment One Gain Loss On Disposal Of Property Plant And Equipment One. Total Flutter shareholders’ equity Parent [Member] Purchase of long lived assets with accrued expense - investing Capital Expenditures Incurred but Not yet Paid, Investing Activities Capital Expenditures Incurred but Not yet Paid, Investing Activities Income taxes receivable Income Taxes Receivable, Current Name Awards Close in Time to MNPI Disclosures, Individual Name Stock options vested (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested, Number of Shares Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Aggregate intrinsic value, outstanding Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value Business acquisitions (including contingent consideration) Business Acquisition Including Contingent Consideration Business acquisition including contingent consideration. Cancelled/Lapsed (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period Schedule of Other Current Liabilities Other Current Liabilities [Table Text Block] General and administrative expenses General and Administrative Expense Impairment charge before income tax Asset, Impairment Charge, Before Tax Asset, Impairment Charge, Before Tax Fair Value by Liability Class [Domain] Fair Value by Liability Class [Domain] Loss on settlement of long-term debt Gain (Loss) On Settlement Of Long Term Debt One Gain (Loss) On Settlement Of Long Term Debt One. 2024 Incentive Plan 2024 Incentive Plan [Member] 2024 Incentive Plan Contingent consideration Contingentent Consideration [Member] Contingentent Consideration [Member] Adjustment to Compensation: Adjustment to Compensation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Acquisition of NSX Adjustment to Additional Paid In Capital, Acquisition Adjustment to Additional Paid In Capital, Acquisition Settlements Redeemable Noncontrolling Interest, Settlements Redeemable Noncontrolling Interest, Settlements Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Interest paid Interest Paid, Excluding Capitalized Interest, Operating Activity Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Other commitments Total commitment Other Commitment Liability-Classified Awards Liability-Classified Awards [Member] Liability-Classified Awards Hedging Designation [Axis] Hedging Designation [Axis] Foreign currency forward contracts Foreign Exchange Forward [Member] Credit Facility [Axis] Credit Facility [Axis] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount  Total Assets, Fair Value Disclosure Thereafter Other Commitments Due After Year Four Other commitments due after year four. Name Measure Name INCOME TAXES Income Tax Disclosure [Text Block] Accounts payable Accounts Payable, Current Pay vs Performance Disclosure [Line Items] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Other (income) expense, net Other Noncash Income (Expense) Acquisition of redeemable non-controlling interests Noncontrolling Interest, Increase from Business Combination Claims against the guarantee Claims Against The Guarantee Claims against the guarantee. Debt Instrument [Line Items] Debt Instrument [Line Items] Schedule of Derivatives Instruments Statements of Financial Performance and Financial Position, Location Schedule of Derivatives Instruments Statements of Financial Performance and Financial Position, Location [Table Text Block] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Purchase consideration Business Combination, Consideration Transferred Additional paid-in capital Additional Paid-in Capital [Member] Entity Filer Category Entity Filer Category Number of indefinite-lived bank guarantees Number of Indefinite-Lived Bank Guarantees Number of Indefinite-Lived Bank Guarantees Proceeds from disposal of intangible assets Proceeds from Sale of Intangible Assets Guarantor Obligations, Nature [Domain] Guarantor Obligations, Nature [Domain] Goodwill impairment Goodwill, impairment loss Goodwill, Impairment Loss Name Trading Arrangement, Individual Name Share-based compensation – liability classified Share Based Compensation Classified as Liability Share based compensation classified as liability. Other liabilities at fair value  Fox Option liability Other Liabilities, Fair Value Disclosure Cash and cash equivalents Cash and Cash Equivalent Fox option liability Equity Option [Member] Equity Option Prepaid Expense and Other Assets, Current [Abstract] Prepaid Expense and Other Assets, Current [Abstract] Non-cash transaction costs on issuance of long-term debt Debt Issuance Costs Incurred During Noncash or Partial Noncash Transaction Probabiltiy Of Market Participant Submitting And Obtaining License Probabiltiy Of Market Participant Submitting And Obtaining License [Member] Probabiltiy Of Market Participant Submitting And Obtaining License [Member] Capitalized software Payments for Software Company Selected Measure Amount Company Selected Measure Amount Schedule of Segment Reporting, Reconciliation of Profit (Loss) by Segment to Consolidated Segment Reporting, Reconciliation of Profit (Loss) by Segment to Consolidated [Table Text Block] Income tax expense (benefit), goods and services tax Income Tax Expense (Benefit), Goods and Services Tax Income Tax Expense (Benefit), Goods and Services Tax Not Designated as Hedging Instrument Not Designated as Hedging Instrument [Member] USD First Lien Term Loan A due 2028 USD First Lien Term Loan A Due 2028 [Member] USD first lien term loan a due 2028. Depreciation and amortization Depreciation and amortization Depreciation, Depletion and Amortization 2027 Other Commitment, to be Paid, Year One  Redeemable non-controlling interests at fair value Redeemable Non Controlling Interests Equity Fair Value Redeemable non controlling interests equity fair value. 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