Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Trading Arrangement: Trading Arrangement [Axis] Maximum Maximum [Member] Title of 12(b) Security Title of 12(b) Security Subsequent event Subsequent Event [Member] Derivative Instruments, Gain (Loss) by Hedging Relationship, by Income Statement Location, by Derivative Instrument Risk [Table] Derivative Instruments, Gain (Loss) [Table] eDOCS eDOCS [Member] eDOCS Adjustment to Compensation, Amount Adjustment to Compensation Amount Segment Reporting [Abstract] Segment Reporting [Abstract] Schedule of Calculation of Estimated Future Amortization Expense Intangible Asset, Finite-Lived, and Capitalized Cost, Software to be Sold, Leased, or Marketed, Estimated Amortization Expense [Table Text Block] Restructuring Plan [Axis] Restructuring Plan [Axis] Other assets Disposal Group, Including Discontinued Operation, Other Assets Present value Asset Retirement Obligation Present Value The present value of a liability for an asset retirement obligation associated with the disposal or retirement of a tangible long-lived asset that results from acquisition, construction or development, or the normal operations of a long-lived asset including obligations from operating leases. Portfolio Portfolio - Product [Member] Portfolio - Product Accrued salaries, incentives and commissions Employee-related Liabilities, Current Common shares Common Stocks, Including Additional Paid in Capital PENSION PLANS AND OTHER POST-RETIREMENT BENEFITS Retirement Benefits [Text Block] Thereafter Lessee, Operating Lease, Liability, to be Paid, after Year Four Lessee, Operating Lease, Liability, to be Paid, after Year Four Content Content - Cloud Services And Subscriptions [Member] Content - Cloud Services And Subscriptions 2028 Finance Lease, Liability, to be Paid, Year One Derivative Instrument [Axis] Derivative Instrument [Axis] Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Assets Disposal Group, Including Discontinued Operation, Assets [Abstract] Depreciation and amortization of intangible assets Other Depreciation and Amortization ADM Application Delivery Management - Product [Member] Application Delivery Management - Product July 1, 2029 - June 30, 2031 Long-Term Debt, Maturity, Year Three and Four Long-Term Debt, Maturity, Year Three and Four Leases [Abstract] Leases [Abstract] Other comprehensive income (loss)—net of tax: Other Comprehensive Income (Loss), Net of Tax [Abstract] Intangible Asset, Finite-Lived, Acquired [Line Items] Intangible Asset, Finite-Lived, Acquired [Line Items] RELATED PARTY TRANSACTIONS Related Party Transactions Disclosure [Text Block] Twenty Twenty Seven Share Repurchase Plan Twenty Twenty Seven Share Repurchase Plan [Member] Twenty Twenty Seven Share Repurchase Plan Granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross Long-term liabilities: Liabilities, Noncurrent [Abstract] Acquired intangible assets (Note 6) Intangible Asset, Excluding Goodwill, after Accumulated Amortization Beginning balance (in shares) Ending balance (in shares) Unvested grants in period (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number Retirement Benefits [Abstract] Retirement Benefits [Abstract] Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Number of reportable segments Number of Reportable Segments Total current liabilities Liabilities, Current Cybersecurity (Enterprise) Cybersecurity (Enterprise) - Product [Member] Cybersecurity (Enterprise) - Product Derivative liability Derivative Liability, Current EMEA EMEA [Member] Entity Address, City or Town Entity Address, City or Town Granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Total revenues by Product Categories Product [Member] Total Intangible Asset, Finite-Lived, after Accumulated Amortization Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Available-for-sale financial assets Available-for-sale financial assets (Note 7) Prepaid Expenses And Other Assets, Financial Assets, Available-For-Sale Prepaid Expenses And Other Assets, Financial Assets, Available-For-Sale Level 2 Fair Value, Inputs, Level 2 [Member] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Issuance of treasury stock (in shares) Stock Issued During Period, Shares, Treasury Stock Reissued In Connection With Settlement Awards Stock Issued During Period, Shares, Treasury Stock Reissued In Connection With Settlement Awards Total other comprehensive income (loss), net for the period Other Comprehensive Income (Loss), Net of Tax Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Performance target (as a percent) Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Target Based Award, Performance Target Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Target Based Award, Performance Target Pension expense Net pension expense Pension Cost (Reversal of Cost) License License [Member] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Revision of Prior Period, Reclassification, Adjustment Revision of Prior Period, Reclassification, Adjustment [Member] Long-term prepaid expenses and other long-term assets Prepaid Expense and Other Assets, Noncurrent Segment Reporting Segment Reporting [Table Text Block] Use of estimates Use of Estimates, Policy [Policy Text Block] Related Party [Axis] Related and Nonrelated Parties [Axis] Adjusted general and administrative General and Administrative Expense, Excluding Share-Based Compensation Expense General and Administrative Expense, Excluding Share-Based Compensation Expense Contract Balances Revenue from Contract with Customer [Policy Text Block] Other comprehensive income (loss) - net Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Additional tax expense, (as a percent) Income Tax, Penalty Rate Income Tax, Penalty Rate Stock expected to be repurchased, accrual Share Repurchase Program, Shares Expected To Be Repurchase Accrual, Amount Share Repurchase Program, Shares Expected To Be Repurchase Accrual, Amount Client assets Customer-Related Intangible Assets [Member] Schedule of Maturity of Lease Liabilities Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block] ITOM IT Operations Management - Cloud Services And Subscriptions [Member] IT Operations Management - Cloud Services And Subscriptions Document Period End Date Document Period End Date Professional service and other Professional Service And Other [Member] Professional Service And Other [Member] July 1, 2027 - June 30, 2029 Recorded Unconditional Purchase Obligation, to be Paid, Year One and Two Recorded Unconditional Purchase Obligation, to be Paid, Year One and Two Debt instrument face amount Debt Instrument, Face Amount Basic earnings per share Earnings Per Share, Basic [Abstract] 2029 Lessee, Operating Lease, Liability, to be Paid, Year Two Special charges recorded to date Restructuring and Related Cost, Cost Incurred to Date Debt term (in years) Debt Instrument, Term Treasury stock, at cost (4,424,724 and 4,751,257 shares at September 30, 2026 and June 30, 2026, respectively) Treasury Stock, Common, Value Effective interest rate (as a percent) Debt Instrument, Interest Rate, Effective Percentage LEASES Lessor, Operating Leases [Text Block] SUPPLEMENTAL CASH FLOW DISCLOSURES Cash Flow, Supplemental Disclosures [Text Block] Lessee, Lease, Description [Line Items] Lessee, Lease, Description [Line Items] Obligations for future leases Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract] Finance leases Finance Lease, Weighted Average Remaining Lease Term Accumulated other comprehensive income (loss) (Note 19) Accumulated Other Comprehensive Income (Loss), Net of Tax Entity Shell Company Entity Shell Company Operating lease liabilities (Note 4) Operating lease liabilities (current) Operating Lease, Liability, Current EARNINGS PER SHARE Earnings Per Share [Text Block] Earnings Per Share [Abstract] Earnings Per Share [Abstract] Document Fiscal Period Focus Document Fiscal Period Focus Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Trading Symbol Trading Symbol Schedule of Unrecognized Compensation Cost Share-Based Payment Arrangement, Nonvested Award, Cost [Table Text Block] Income taxes payable (Note 13) Accrued Income Taxes, Current Stock repurchase plan, period in force Share Repurchase Program, Period in Force Company Selected Measure Name Company Selected Measure Name Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Diluted earnings per share Earnings Per Share, Diluted [Abstract] Issuance of treasury stock Stock Issued During Period, Value, Treasury Stock Reissued In Connection With Settlement Awards Stock Issued During Period, Value, Treasury Stock Reissued In Connection With Settlement Awards Credit Facility [Domain] Credit Facility [Domain] Cash flows from operating activities: Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Client Support Client Support [Member] Client Support [Member] Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] Useful life (in years) Property, Plant, and Equipment, Useful Life Disposal Group Name [Domain] Disposal Group Name [Domain] 2029 Finance Lease, Liability, to be Paid, Year Two 2031 Finance Lease, Liability, to be Paid, Year Four Accruals and adjustments Restructuring Reserve, Accrual Adjustment Operating Lease, Lease Not yet Commenced Operating Lease, Lease Not yet Commenced [Member] Schedule of Divestiture Disposal Groups, Including Discontinued Operations [Table Text Block] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Gross profit Gross Profit Effect of dilutive securities (in shares) Weighted Average Number of Shares Outstanding, Diluted, Adjustment Schedule of Reconciliation of Changes in Fair Value of Level 3 Investments Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] GOODWILL Goodwill [Text Block] Less: Imputed interest Finance Lease, Liability, Undiscounted Excess Amount Operating leases Operating Lease, Payments Award Timing Predetermined Award Timing Predetermined [Flag] Cybersecurity (SMB & Consumer) Cybersecurity (SMB & Consumer) - Cloud Services And Subscriptions [Member] Cybersecurity (SMB & Consumer) - Cloud Services And Subscriptions Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Share-based compensation APIC, Share-Based Payment Arrangement, Increase for Cost Recognition OT South Africa Open Text South Africa Proprietary Ltd [Member] Open Text South Africa Proprietary Ltd Effective income tax rate (as a percent) Effective Income Tax Rate Reconciliation, Percent Weighted- Average Remaining Contractual  Term (years) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Additional Disclosures [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Additional Disclosures [Abstract] Forfeiture rate (based on historical rates) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Forfeiture Rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Forfeiture Rate Repurchase of Common Shares Stock Repurchased and Retired During Period, Value Senior notes Long-Term Debt, Fair Value Accounts receivable trade, net of allowance for credit losses Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net Plan Name [Domain] Plan Name [Domain] Scenario [Domain] Scenario [Domain] Unconditional Purchase Obligation, Category of Goods or Services Acquired [Domain] Unconditional Purchase Obligation, Category of Goods or Services Acquired [Domain] Outstanding at beginning of period (in dollars per share) Outstanding at end of period (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price Units Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward] Operating lease right of use assets (Note 4) Operating lease right of use assets Operating Lease, Right-of-Use Asset EQUITY AND SHARE-BASED COMPENSATION Shareholders' Equity and Share-Based Payments [Text Block] AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] Operating Leases Operating Lease, Liability [Abstract] Derivative Liability, Statement of Financial Position [Extensible Enumeration] Derivative Liability, Statement of Financial Position [Extensible Enumeration] Operating leases, term of extension option (in years) Lessee, Operating Lease, Renewal Term Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Deferred revenues Disposal Group, Including Discontinued Operation, Deferred Revenue Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Noncontrolling Interest [Line Items] Noncontrolling Interest [Line Items] Schedule of Incremental Costs of Obtaining a Contract with a Customer Capitalized Contract Cost [Table Text Block] Canada Revenue Agency (CRA) Canada Revenue Agency [Member] Expiration Date Trading Arrangement Expiration Date Hedging Relationship [Axis] Hedging Relationship [Axis] Americas Americas [Member] Total shareholders’ equity Beginning balance Ending balance Equity, Including Portion Attributable to Noncontrolling Interest Contract assets Disposal Group, Including Discontinued Operation, Contract with Customer, Asset, after Allowance for Credit Loss, Current Disposal Group, Including Discontinued Operation, Contract with Customer, Asset, after Allowance for Credit Loss, Current Disposal Group, Including Discontinued Operations [Line Items] Disposal Group, Including Discontinued Operations [Line Items] Accounts payable and accrued liabilities Disposal Group, Including Discontinued Operation, Accounts Payable and Accrued Liabilities Exercisable ending balance (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Number Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Derivative [Table] Derivative [Table] Other Income and Expenses [Abstract] Other Income and Expenses [Abstract] Proceeds from issuance of Common Shares from exercise of stock options and ESPP Proceeds from Issuance of Common Stock OTHER INCOME (EXPENSE), NET Other Nonoperating Income and Expense [Text Block] Unamortized debt discount and issuance costs Debt Instrument, Unamortized Discount (Premium), Net Cash flows from investing activities: Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Adjusted sales Selling Expense, Excluding Share-Based Compensation Expense Selling Expense, Excluding Share-Based Compensation Expense Unrecognized Compensation Cost Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] Segments [Domain] Segments [Domain] Scenario [Axis] Scenario [Axis] Total Contractual Obligation Disposal Group Classification [Domain] Disposal Group Classification [Domain] Schedule of Contractual Obligations Contractual Obligation, Fiscal Year Maturity [Table Text Block] Financing costs Debt Issuance Costs, Net Schedule of Restructuring Reserve Restructuring and Related Costs [Table Text Block] Business Combination [Table] Business Combination [Table] PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Secured debt Secured Debt [Member] Business Combination, Asset Acquisition, Transaction between Entities under Common Control, and Joint Venture Formation [Abstract] Content Content - Product [Member] Content - Product Finance leases Finance Lease, Weighted Average Discount Rate, Percent Debt instrument interest rate (as a percent) Debt Instrument, Interest Rate, Stated Percentage Accrued interest on long-term debt Accrued Interest On Long-Term Debt Accrued Interest On Long-Term Debt Dividends declared Dividends, Common Stock, Cash Total OpenText shareholders’ equity Equity, Attributable to Parent Disposal by sale Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] ASSETS Assets [Abstract] Insider Trading Policies and Procedures [Line Items] ACCOUNTS PAYABLE AND ACCRUED LIABILITIES Accounts Payable and Accrued Liabilities Disclosure [Text Block] Schedule of Nonvested Share Activity Schedule of Nonvested Share Activity [Table Text Block] Accounts receivable trade, allowance for credit losses Accounts Receivable, Allowance for Credit Loss, Current PSUs Performance Share Units (issued under LTIP) Performance Shares [Member] Prepaid expenses and other current assets (Note 7) Total Prepaid Expense and Other Assets, Current Deferred taxes Deferred Income Tax Expense (Benefit) Awards purchase price discount (as a percent) Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price Discount Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price Discount Interest and other related expense, net Interest and other related expense, net Interest Income (Expense), Nonoperating Special charges (recoveries) (Note 16) Total Special charges (recoveries) Restructuring, Settlement and Impairment Provisions Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Line Items] Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Line Items] Excluded as anti-dilutive (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Capitalized costs to obtain a contract Capitalized Contract Cost, Net, Noncurrent Schedule of Changes in Goodwill Goodwill [Table Text Block] Entity Central Index Key Entity Central Index Key Accumulated depreciation Property, Plant, and Equipment, Accumulated Depreciation, Depletion, and Amortization Equity [Abstract] Equity [Abstract] Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Total Liabilities Disposal Group, Including Discontinued Operation, Liabilities October 1, 2026 - June 30, 2027 Long-Term Debt, Maturity, Remainder of Fiscal Year Other comprehensive income (loss) before reclassifications, net of tax Other Comprehensive Income (Loss), before Reclassifications, Net of Tax Ownership [Axis] Ownership [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Designated as hedging instrument Derivatives designated as hedges: Designated as Hedging Instrument [Member] Period of continued involvement after disposal Disposal Group, Including Discontinued Operation, Period Of Continued Involvement After Disposal Disposal Group, Including Discontinued Operation, Period Of Continued Involvement After Disposal Schedule of Weighted-Average Fair Value of Options and Weighted-Average Assumptions Used Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Restructuring, Settlement and Impairment Provisions [Abstract] Restructuring, Settlement and Impairment Provisions [Abstract] Gain (loss) reclassified from AOCI into income (excluded from effectiveness testing) - net investment hedge Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), Reclassification, before Tax Options Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward] Interest addition to floating rate (as a percent) Debt Instrument, Basis Spread on Variable Rate Enterprise Assessment And Other Miscellaneous Charges Enterprise Assessment And Other Miscellaneous Charges [Member] Enterprise Assessment And Other Miscellaneous Charges Total lease payments Finance Lease, Liability, to be Paid Accumulated Other Comprehensive Income Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] All Individuals All Individuals [Member] Payments of dividends to shareholders Payments of dividends Payments of Dividends 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] Weighted Average Recognition Period (years) Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Previously Reported Previously Reported [Member] Leverage ratio, compliance maximum Debt Instrument, Covenant, Leverage Ratio, Maximum Debt Instrument, Covenant, Leverage Ratio, Maximum ACQUIRED INTANGIBLE ASSETS Intangible Asset [Text Block] Statement [Line Items] Statement [Line Items] Total assets Assets Defined Benefit Plan [Table] Defined Benefit Plan [Table] Finance lease receivables (current) Finance Lease, Receivables, Current Finance Lease, Receivables, Current Weighted-average fair value of options granted (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Average exercised share price (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Average Exercise Price October 1, 2026 - June 30, 2027 Contractual Obligation, to be Paid, Remainder of Fiscal Year PEO PEO [Member] Goodwill (Note 5) Beginning balance Ending balance Goodwill Retirement Plan Type [Axis] Retirement Plan Type [Axis] Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Retained Earnings Retained Earnings [Member] Long-term operating lease liabilities (Note 4) Operating lease liabilities (non-current) Operating Lease, Liability, Noncurrent Total operating expenses Operating Expenses Revolving Credit Facility Revolving Credit Facility [Member] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Award Timing Disclosures [Line Items] Foreign Currency Translation Adjustments Accumulated Foreign Currency Adjustment Attributable to Parent [Member] Earnings per share—diluted attributable to OpenText (Note 21) (in dollars per share) Diluted earnings per share attributable to OpenText (in dollars per share) Earnings Per Share, Diluted Prepaid expenses and other current assets Increase (Decrease) in Prepaid Expense and Other Assets Amortization of acquired client-based intangible assets (Note 6) Amortization of acquired client-based intangible assets Intangible Asset, Finite-Lived, Amortization Expense Ownership [Domain] Ownership [Domain] Total other comprehensive income, net Other Comprehensive Income (Loss), Net of Tax, Including Portion Attributable To Noncontrolling Interest Other Comprehensive Income (Loss), Net of Tax, Including Portion Attributable To Noncontrolling Interest Share-based Payment Arrangement [Abstract] Share-Based Payment Arrangement [Abstract] Total revenues Revenue from Contract with Customer, Excluding Assessed Tax Cloud services and subscriptions Cloud Services And Subscriptions [Member] Cloud Services And Subscriptions [Member] Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Schedule of Effects of Derivative Instruments on Income and Other Comprehensive Income (OCI) Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) [Table Text Block] Total Expected Payments For Debt Obligations Expected Payments For Debt Obligations Acquisition Term Loan Acquisition Term Loan [Member] Acquisition Term Loan Adjusted research and development Research and Development Expense (Excluding Acquired In Process Cost, and Share-Based Compensation Expense) Research and Development Expense (Excluding Acquired In Process Cost, and Share-Based Compensation Expense) Equity Method Investment [Table] Equity Method Investment [Table] Total Derivative, Gain (Loss) on Derivative, Net Income from operations Operating Income (Loss) Total cloud services and subscriptions revenues by Product Categories Service [Member] Weighted-average remaining lease term Weighted-Average Remaining Lease Term [Abstract] Weighted-Average Remaining Lease Term Remaining performance obligation Revenue, Remaining Performance Obligation, Amount 2027 (nine months ending) Finance Lease, Liability, to be Paid, Remainder of Fiscal Year Unrealized gain (loss) on cash flow hedges: Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax [Abstract] Senior Secured Notes 2031 Senior Secured Notes 2031 [Member] Senior Secured Notes 2031 ACQUISITIONS AND DIVESTITURES Business Combination [Text Block] Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Service cost Defined Benefit Plan, Service Cost Repurchase and retirement of common stock Stock Repurchased and Retired During Period, Value, Inclusive Of Tax Stock Repurchased and Retired During Period, Value, Inclusive Of Tax Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Common stock, shares issued (in shares) Common Stock, Shares, Issued Beginning balance Ending balance Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Less: Long-Term Debt, Current and Noncurrent [Abstract] Amortization of actuarial (gain) loss into net income - net of tax expense (recovery) Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, Tax ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) Comprehensive Income (Loss) Note [Text Block] Cost of revenues: Cost of Goods and Service, Excluding Depreciation, Depletion, and Amortization Product and Service [Domain] Product and Service [Domain] Deferred Share Unit Plan Deferred Share Unit Plan [Member] Deferred Share Unit Plan Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Amounts payable in respect of restructuring and other special charges Restructuring Reserve, Current Deferred tax liabilities (Note 13) Deferred Income Tax Liabilities, Net Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Gain (loss) or derivatives not designated as hedging instruments, net Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net Number of pension and postretirement plans (in plans) Number Of Pension And Postretirement Plans Number Of Pension And Postretirement Plans 2030 Lessee, Operating Lease, Liability, to be Paid, Year Three Termination Date Trading Arrangement Termination Date Noncontrolling Interest [Table] Noncontrolling Interest [Table] Adjusted marketing Marketing Expense, Excluding Share-Based Compensation Expense Marketing Expense, Excluding Share-Based Compensation Expense Cash received during the period for interest Interest Received, Net Interest Received, Net Subsequent Events [Abstract] Subsequent Events [Abstract] Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Analytics Analytics - Cloud Services And Subscriptions [Member] Analytics - Cloud Services And Subscriptions Interest and penalties accrued Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued Derivative asset Derivative Asset, Current Accrued liabilities Accrued Liabilities, Current Fair Value as of Grant Date Award Grant Date Fair Value Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Arrangement Duration Trading Arrangement Duration Capitalized costs to obtain a contract Capitalized Contract Cost, Net, Current Entity Address, Postal Zip Code Entity Address, Postal Zip Code Entity Registrant Name Entity Registrant Name Weighted-average assumptions used: Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions and Methodology [Abstract] Termination payment Payment For Termination Of Derivative Contract Payment For Termination Of Derivative Contract Schedule of Non Option Award Activity Share-Based Payment Arrangement, Performance Shares, Activity [Table Text Block] Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Analytics Analytics - Product [Member] Analytics - Product Deposits and restricted cash Restricted Cash and Investments, Current Cost Intangible Asset, Finite-Lived, before Accumulated Amortization Share in net (income) of equity investees OpenText share in net income of equity investees OpenText share in net income of equity investees Income (Loss) from Equity Method Investments Other Assets [Abstract] Accounts payable and accrued liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities Stock repurchase plan, maximum percent of public float of common shares Share Repurchase Program, Authorized, Percent Of Public Float Of Common Shares Share Repurchase Program, Authorized, Percent Of Public Float Of Common Shares Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Award vesting period (in years) Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period Goodwill [Roll Forward] Goodwill [Roll Forward] Intangible Asset, Finite-Lived, Class [Domain] Intangible Asset, Finite-Lived, Class [Domain] Exercisable (in years) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted-Average Remaining Contractual Term Schedule of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Award Type [Domain] Award Type [Domain] Long-term operating lease liabilities Disposal Group, Including Discontinued Operation, Operating Lease Liabilities Noncurrent Disposal Group, Including Discontinued Operation, Operating Lease Liabilities Noncurrent 2027 (nine months ending) Lessee, Operating Lease, Liability, to be Paid, Remainder of Fiscal Year FAIR VALUE MEASUREMENT Fair Value Disclosures [Text Block] Level 3 Fair Value, Inputs, Level 3 [Member] Expected life (in years) Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term 2028 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year One Operating leases, term of contract (in years) Lessee, Operating Lease, Term of Contract Common stock, shares authorized (in shares) Common Stock, Shares Authorized, Unlimited [Fixed List] Ownership by noncontrolling owners (as a percent) Subsidiary, Ownership Percentage, Noncontrolling Owner Geographical [Axis] Geographical [Axis] Restricted cash Restricted Cash July 1, 2031 and beyond Unrecorded Unconditional Purchase Obligation, to be Paid, After Year Five Unrecorded Unconditional Purchase Obligation, to be Paid, After Year Five Interest expense Interest Expense, Debt Senior Secured Notes 2033 Senior Secured Notes 2033 [Member] Senior Secured Notes 2033 Lessee, Lease, Description [Table] Lessee, Lease, Description [Table] Cash, cash equivalents and restricted cash at beginning of the period Cash, cash equivalents and restricted cash at end of the period Total cash, cash equivalents and restricted cash Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Issuance of treasury stock Stock Issued During Period, Value, Treasury Stock Reissued Non-NEOs Non-NEOs [Member] Undiscounted value Asset Retirement Obligation Undiscounted Value Asset Retirement Obligation Undiscounted Value 2029 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year Two Schedule of Long-Term Debt Schedule of Debt [Table Text Block] Portfolio Portfolio - Cloud Services And Subscriptions [Member] Portfolio - Cloud Services And Subscriptions LEASES Lessee, Operating Leases [Text Block] Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Cybersecurity (Enterprise) Cybersecurity (Enterprise) - Cloud Services And Subscriptions [Member] Cybersecurity (Enterprise) - Cloud Services And Subscriptions Repurchase of Common Shares Payments for Repurchase of Common Stock Deferred revenues (Note 3) Short-term deferred revenues Contract with Customer, Liability, Current Pension liability, net Disposal Group, Including Discontinued Operation, Pension Liability Disposal Group, Including Discontinued Operation, Pension Liability Statistical Measurement [Axis] Statistical Measurement [Axis] Gain (loss) recognized in OCI (loss) on cash flow and net investment hedge (effective portion) Gain (loss) recognized in OCI (loss) on cash flow hedge (effective portion) Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax Award Type [Axis] Award Type [Axis] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Retained earnings Retained Earnings (Accumulated Deficit) Product and Service [Axis] Product and Service [Axis] July 1, 2031 and beyond Long-Term Debt, Maturity, after Year Four Long-Term Debt, Maturity, after Year Four Other historical restructuring plans Other Historical Restructuring Plans [Member] Other Historical Restructuring Plans Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Pension Plan Pension Plan [Member] Operating lease cost Operating Lease, Cost New capitalized costs incurred Capitalized Contract Costs Incurred Capitalized Contract Costs Incurred Expected dividend yield Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Dividend Rate Fiscal years ending June 30, Intangible Asset, Finite-Lived, after Accumulated Amortization, Estimated Amortization Expense, Fiscal Year Maturity [Abstract] Operating lease assets and liabilities, net Increase (Decrease) in Operating Lease Assets and Liabilities, Net Increase (Decrease) in Operating Lease Assets and Liabilities, Net Derivative Contract Type [Domain] Derivative Contract [Domain] October 1, 2026 - June 30, 2027 Unrecorded Unconditional Purchase Obligation, to be Paid, Year One Impact of foreign exchange rate changes Goodwill, Foreign Currency Translation, Gain (Loss) Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Senior Notes 2028 Senior Notes 2028 [Member] Senior Notes 2028 [Member] Total liabilities and shareholders’ equity Liabilities and Equity Tax Years 2020, and 2021 Tax Years 2020, and 2021 [Member] Tax Years 2020, and 2021 Variable lease cost Variable Lease, Cost SPECIAL CHARGES (RECOVERIES) Restructuring, Impairment, and Other Activities Disclosure [Text Block] Stock Options (issued under Stock Option Plans) Stock Options Share-Based Payment Arrangement, Option [Member] Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Table] Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Table] Asset retirement obligations Asset Retirement Obligation, Current Non-controlling interests Equity, Attributable to Noncontrolling Interest Segments [Axis] Segments [Axis] Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Schedule of Fair Value of Derivative Instruments in the Condensed Consolidated Balance Sheets Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block] Related Party [Domain] Related and Nonrelated Parties [Domain] Special charges Restructuring Charges Tabular List, Table Tabular List [Table Text Block] Amortization of actuarial (gain) loss into net income - net of tax Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, after Tax 7 Year EUR to USD Market Hedge Seven Year Euro to US Dollar Cross Currency Swap [Member] Seven Year Euro to US Dollar Cross Currency Swap Expected volatility Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Weighted Average Volatility Rate 2030 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year Three 2027 (nine months ending) Intangible Asset, Finite-Lived, Estimated Amortization Expense, Remainder of Fiscal Year Income taxes recoverable (Note 13) Income Taxes Receivable, Current Name Awards Close in Time to MNPI Disclosures, Individual Name 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] Outstanding Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value Cash payments Payments (Recoveries) For Restructuring Payments (Recoveries) For Restructuring Long-Lived Asset, Class [Domain] Long-Lived Asset, Class [Domain] Tax Year 2016 Tax Year 2016 [Member] Senior Notes 2029 Senior Notes 2029 [Member] Senior Notes 2029 Adjustment to Compensation: Adjustment to Compensation [Axis] Amounts reclassified into net income, net of tax Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Restructuring Cost and Reserve [Line Items] Restructuring Cost and Reserve [Line Items] July 1, 2029 - June 30, 2031 Recorded Unconditional Purchase Obligation, to be Paid, Year Three and Four Recorded Unconditional Purchase Obligation, to be Paid, Year Three and Four Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Cash paid during the period for interest Interest Paid, Excluding Capitalized Interest, Operating Activity Additions of property and equipment Payments to Acquire Productive Assets Hedging Designation [Axis] Hedging Designation [Axis] Credit Facility [Axis] Credit Facility [Axis] Long Term Incentive Plan Long Term Incentive Plan [Member] Long Term Incentive Plan [Member] Name Measure Name Pay vs Performance Disclosure [Line Items] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy and NAV [Domain] Debt Instrument [Line Items] Debt Instrument [Line Items] Tax Year 2015 Tax Year 2015 [Member] Equipment Equipment [Member] Limited Partner Investments Limited Partner Investments Limited Partner Investments [Member] Limited Partner Investments Name Trading Arrangement, Individual Name Cash and cash equivalents Cash and cash equivalents Cash and Cash Equivalent Company Selected Measure Amount Company Selected Measure Amount Tax Period [Domain] Tax Period [Domain] Operating leases Operating Lease, Weighted Average Remaining Lease Term Non-PEO NEO Non-PEO NEO [Member] Depreciation Depreciation, Nonproduction Foreign exchange gains (losses) Gain (Loss), Foreign Currency Transaction, before Tax Total cost of revenues Cost of Product and Service Sold Technology assets Technology-Based Intangible Assets [Member] Award Timing Method Award Timing Method [Text Block] Increase (decrease) in cash, cash equivalents and restricted cash during the period Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation Forecast Forecast [Member] Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Amortization of actuarial (gains) losses Defined Benefit Plan, Amortization of Gain (Loss) Tax Year 2012 Tax Year 2012 [Member] Net income attributable to OpenText Net income attributable to OpenText Net income attributable to OpenText Net Income (Loss) Attributable to Parent Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Optional extension term Disposal Group, Including Discontinued Operation, Period Of Continued Involvement After Disposal, Optional Extension Term Disposal Group, Including Discontinued Operation, Period Of Continued Involvement After Disposal, Optional Extension Term Business Optimization Plan Business Optimization Plan [Member] Business Optimization Plan Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] Restatement Determination Date: Restatement Determination Date [Axis] Tax Year 2013 Tax Year 2013 [Member] Schedule of Accumulated Other Comprehensive Income (Loss) Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Exercisable at end of period (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Exercise Price Leases Lessee, Leases [Policy Text Block] Accounts receivable Increase (Decrease) in Receivables Schedule of Components of Prepaid Expenses and Other Assets Schedule of Other Assets [Table Text Block] Revenues Revenues [Abstract] July 1, 2029 - June 30, 2031 Unrecorded Unconditional Purchase Obligation, to be Paid, Year Four and Five Unrecorded Unconditional Purchase Obligation, to be Paid, Year Four and Five Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Tax Year 2014 Tax Year 2014 [Member] Weighted- average remaining contractual term (years) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted-Average Remaining Contractual Term Statistical Measurement [Domain] Statistical Measurement [Domain] Document Fiscal Year Focus Document Fiscal Year Focus Asset impairment Contract with Customer, Asset, Credit Loss Expense (Reversal) Expected timing of satisfaction, period Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Operating lease right of use assets Disposal Group, Including Discontinued Operation, Operating Lease, Right-of-Use Asset Disposal Group, Including Discontinued Operation, Operating Lease, Right-of-Use Asset 2028 Lessee, Operating Lease, Liability, to be Paid, Year One Schedule of Restricted Stock Activity Share-Based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block] Workforce reduction Workforce Reductions [Member] Workforce Reductions Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Over time (including professional service and other revenue) Transferred over Time [Member] Line of credit Line of Credit [Member] Restatement Determination Date Restatement Determination Date Expected return of plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Other charges (recoveries) Restructuring Charges (Recoveries), Other Restructuring Charges (Recoveries), Other Geographic concentration percentage of pension obligations Defined Benefit Plan, Percentage Of Pension Obligations by Geographic Location Defined Benefit Plan, Percentage Of Pension Obligations by Geographic Location July 1, 2027 - June 30, 2029 Contractual Obligation, To Be Paid, Year One And Two Contractual Obligation, To Be Paid, Year One And Two Amendment Flag Amendment Flag Current liabilities: Liabilities, Current [Abstract] Liabilities Disposal Group, Including Discontinued Operation, Liabilities [Abstract] Disposal Group Classification [Axis] Disposal Group Classification [Axis] Loss Contingencies [Table] Loss Contingencies [Table] Disposal Group, Held-for-Sale, Not Discontinued Operations Disposal Group, Held-for-Sale, Not Discontinued Operations [Member] October 1, 2026 - June 30, 2027 Recorded Unconditional Purchase Obligation, to be Paid, Remainder of Fiscal Year Timing of Transfer of Good or Service [Domain] Timing of Transfer of Good or Service [Domain] Total long-term liabilities Liabilities, Noncurrent Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Property and equipment Disposal Group, Including Discontinued Operation, Property, Plant, and Equipment Entity Address, State or Province Entity Address, State or Province PEO Total Compensation Amount PEO Total Compensation Amount Net foreign currency translation adjustments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Notional amount of forward contracts held to sell U.S. dollars in exchange for Canadian dollars Derivative, Notional Amount Share Repurchase Program [Domain] Share Repurchase Program [Domain] Weighted average number of Common Shares outstanding—basic (in shares) Basic (in shares) Weighted Average Number of Shares Outstanding, Basic Contract assets (Note 3) Short-term contract assets Contract with Customer, Asset, after Allowance for Credit Loss, Current Loss Contingencies [Line Items] Loss Contingencies [Line Items] Net change in transition services agreement obligation Divestiture Of Businesses, Net Change In Transition Asset (Obligation) Divestiture Of Businesses, Net Change In Transition Asset (Obligation) 2031 Lessee, Operating Lease, Liability, to be Paid, Year Four Accrued liabilities (Note 8) Total Non current Accounts Payable And Accrued Liabilities Plus Other Accruals Non current Accounts Payable And Accrued Liabilities Plus Other Accruals Schedule of Supplemental Disclosure of Cash Flow Information Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Cybersecurity (SMB & Consumer) Cybersecurity (SMB & Consumer) - Product [Member] Cybersecurity (SMB & Consumer) - Product Total Assets Disposal Group, Including Discontinued Operation, Assets Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Vested (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period July 1, 2029 - June 30, 2031 Contractual Obligation, to be Paid, Year Three and Four Contractual Obligation, to be Paid, Year Three and Four Accumulated Amortization Intangible Asset, Finite-Lived, Accumulated Amortization Sublease income Sublease Income Credit agreement, maximum capacity Line of Credit Facility, Maximum Borrowing Capacity Board of Directors Chairman Board of Directors Chairman [Member] Current portion of long-term debt (Note 9) Current portion of long-term debt Long-Term Debt, Current Maturities Location, Statement of Other Comprehensive Income, Balance [Axis] Location, Statement of Other Comprehensive Income, Balance [Axis] Reduction of applicable interest rate margin Debt Instrument, Basis Spread On Variable Rate, Reduction Debt Instrument, Basis Spread On Variable Rate, Reduction Accounting Pronouncements Adopted in Fiscal 2026 and Accounting Pronouncements Not Yet Adopted in Fiscal 2027 New Accounting Pronouncements, Policy [Policy Text Block] Land Land [Member] Deferred revenues Increase (Decrease) in Contract with Customer, Liability Loss on sale and write down of property and equipment, net Gain (Loss) on Disposition of Property Plant Equipment Non-Controlling Interests Noncontrolling Interest [Member] Unrealized gain (loss) - net of tax expense (recovery) Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax Amortization of debt discount and issuance costs Amortization of Debt Issuance Costs Schedule of Long-Term Accrued Liabilities Schedule of Accrued Liabilities [Table Text Block] July 1, 2027 - June 30, 2029 Long Term Debt, Maturity, Year One and Two Long Term Debt, Maturity, Year One and Two Total amount outstanding Long-Term Debt Deposits and restricted cash Restricted Cash and Investments, Noncurrent Changes in operating assets and liabilities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] Forfeited or expired (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures and Expirations in Period Net cash used in investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Unrecognized tax benefits Unrecognized Tax Benefits Contract assets Increase (Decrease) in Contract with Customer, Asset Security Exchange Name Security Exchange Name Granted (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Transition services receivable Disposal Group, Not Discontinued Operation, Transition Services Receivable Disposal Group, Not Discontinued Operation, Transition Services Receivable Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Name Outstanding Recovery, Individual Name Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Geographical [Domain] Geographical [Domain] Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Reportable Segment Reportable Segment [Member] Reportable Segment Senior Notes 2030 Senior Notes 2030 [Member] Senior Notes 2030 [Member] Changes in derivative instruments Unrealized gains (losses) on derivatives not designated as hedges Unrealized Gain (Loss) on Derivatives Ownership by open text (as a percent) Subsidiary, Ownership Percentage, Parent Defined Benefit Pension Plans Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Total principal payments due Long-Term Debt, Gross Senior Notes 2031 Senior Notes 2031 [Member] Senior Notes 2031 Related Party Transactions [Abstract] Beginning balance (in shares) Ending balance (in shares) Shares, Issued Compensation Amount Outstanding Recovery Compensation Amount Amortization of capitalized costs Capitalized Contract Cost, Amortization Individual: Individual [Axis] Weighted average number of Common Shares outstanding—diluted (in shares) Diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted July 1, 2027 - June 30, 2029 Unrecorded Unconditional Purchase Obligation, to be Paid, Year Two And Three Unrecorded Unconditional Purchase Obligation, to be Paid, Year Two And Three Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Entity Emerging Growth Company Entity Emerging Growth Company Related Party Transaction [Line Items] Related Party Transaction [Line Items] Pension liability, net (Note 10) Liability, Defined Benefit Plan, Noncurrent Underlying Security Market Price Change Underlying Security Market Price Change, Percent DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES Derivative Instruments and Hedging Activities Disclosure [Text Block] Aggregate  Intrinsic Value ($’000's) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value, Additional Disclosures [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value, Additional Disclosures [Abstract] Operating leases Right-Of-Use Asset Obtained In Exchange For Operating Lease Liability, Net Of Modifications Right-Of-Use Asset Obtained In Exchange For Operating Lease Liability, Net Of Modifications Less: Imputed interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] Cost of revenues: Cost of Revenue [Abstract] Treasury Stock Treasury Stock, Common [Member] Intangible Asset, Goodwill and Other [Abstract] Intangible Asset, Goodwill and Other [Abstract] Business Network Business Network - Product [Member] Business Network - Product Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Total lease payments Lessee, Operating Lease, Liability, to be Paid Beginning balance (in dollars per share) Ending balance (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value July 1, 2031 and beyond Recorded Unconditional Purchase Obligation, to be Paid, after Year Four Recorded Unconditional Purchase Obligation, to be Paid, after Year Four All Executive Categories All Executive Categories [Member] Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Long-term contract assets Disposal Group, Including Discontinued Operation, Operating Lease, Contract with Customer, Asset, after Allowance for Credit Loss, Noncurrent Disposal Group, Including Discontinued Operation, Operating Lease, Contract with Customer, Asset, after Allowance for Credit Loss, Noncurrent Schedule of Components of Net Pension Expense for Pension Plan Schedule of Net Benefit Costs [Table Text Block] Acquired intangible assets Disposal Group, Including Discontinued Operation, Intangible Assets Sales and marketing Selling and Marketing Expense Actuarial gain (loss) relating to defined benefit pension plans: Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax [Abstract] Finance Leases Finance Lease, Liability [Abstract] Issuance of treasury stock (in shares) Stock Issued During Period, Shares, Treasury Stock Reissued Number of product categories Number Of Product Categories Number Of Product Categories Schedule of Basic Earnings (Loss) Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Finance Leases Finance Lease, Assets And Liabilities, Lessee [Abstract] Finance Lease, Assets And Liabilities, Lessee Debt Disclosure [Abstract] Debt Disclosure [Abstract] Estimated amount of loss resulting from an adverse tax position Income Tax Examination, Estimate of Possible Loss SEGMENT INFORMATION Segment Reporting [Text Block] Minimum Minimum [Member] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Schedule of Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] Weighted-average number of shares outstanding (in ‘000’s) Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Foreign exchange gain (loss) on cash held in foreign currencies Effect of Exchange Rate on Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Location, Statement of Income, Balance [Axis] Location, Statement of Income, Balance [Axis] Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Outstanding (in years) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted-Average Remaining Contractual Term Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Timing of Transfer of Good or Service [Axis] Timing of Transfer of Good or Service [Axis] Business Combination [Line Items] Business Combination [Line Items] Other Plans Other Plans Other Plans [Member] Other Plans [Member] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Total Recorded Unconditional Purchase Obligation Exercise Price Award Exercise Price Restructuring Cost [Table] Restructuring Cost [Table] Facility charges Facility Closing [Member] Facility fee expense Facility Fee Expense, Amount Facility Fee Expense, Amount Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Contract assets reclassified to receivables Contract with Customer, Asset, Reclassified to Receivable Document Quarterly Report Document Quarterly Report Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Common Shares and Additional Paid in Capital Common Stock Including Additional Paid in Capital [Member] Repayment of long-term debt and Revolver Repayments of Long-Term Debt Long-term contract assets (Note 3) Long-term contract assets Contract with Customer, Asset, after Allowance for Credit Loss, Noncurrent PREPAID EXPENSES AND OTHER ASSETS Investments and Other Noncurrent Assets [Text Block] Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Investments Equity Method Investments Balance, beginning Balance, ending Restructuring Reserve Equity Component [Domain] Equity Component [Domain] Loss recognized in income Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings Long-term deferred revenues Disposal Group, Including Discontinued Operation, Deferred Revenue, Noncurrent Adoption Date Trading Arrangement Adoption Date Micro Focus Micro Focus [Member] Micro Focus Schedule of Other Income (Expense), Net Schedule of Other Nonoperating Income (Expense) [Table Text Block] eDOCS consideration to be received Disposal Group, Including Discontinued Operation, Consideration Counterparty Name [Domain] Counterparty Name [Domain] Other income (expense), net (Note 21) Other (income) expense, net Total other income (expense), net Nonoperating Income (Expense) Restructuring Type [Axis] Restructuring Type [Axis] 5 Year EUR to USD Market Hedge Five Year Euro to US Dollar Cross Currency Swap [Member] Five Year Euro to US Dollar Cross Currency Swap Title Trading Arrangement, Individual Title Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Accounting Policies [Abstract] Accounting Policies [Abstract] Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Risk–free interest rate Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Total operating lease liabilities Total Operating Lease, Liability Decrease in cost Intangible Asset, Finite-Lived, Period Increase (Decrease) Outstanding at beginning of period (in shares) Outstanding at end of period (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number Total finance lease liabilities Total Finance Lease, Liability Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Repayment of line of credit Repayments of Debt Type of Restructuring [Domain] Type of Restructuring [Domain] Business Combination [Domain] Business Combination [Domain] Purchase obligations for contracts not accounted for as lease obligations Recorded Unconditional Purchase Obligation, Fiscal Year Maturity Schedule [Abstract] Business Network Business Network - Cloud Services And Subscriptions [Member] Business Network - Cloud Services And Subscriptions Forfeited or expired (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Restricted Share Units (issued under LTIP) Restricted Share Units Restricted Stock Units (RSUs) [Member] All Adjustments to Compensation All Adjustments to Compensation [Member] Business Combination [Axis] Business Combination [Axis] Net cash provided by operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Revenue, remaining performance obligation (as a percent) Revenue, Remaining Performance Obligation, Percentage Income Statement [Abstract] Income Statement [Abstract] Shareholders’ equity: Equity, Attributable to Parent [Abstract] Under employee stock purchase plans (in shares) Stock Issued During Period, Shares, Employee Stock Purchase Plans Document Transition Report Document Transition Report Restructuring Plan [Domain] Restructuring Plan [Domain] Operating expenses: Operating Expenses [Abstract] Deferred tax assets (Note 13) Deferred Income Tax Assets, Net Total recurring revenues Cloud Revenues And Customer Support Revenues [Member] Cloud Revenues And Customer Support Revenues [Member] Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Intangible Asset, Finite-Lived, Acquired [Table] Intangible Asset, Finite-Lived, Acquired [Table] City Area Code City Area Code SUBSEQUENT EVENTS Subsequent Events [Text Block] Write-off of right of use assets Operating Lease, Right-of-Use Asset, Periodic Reduction Name Forgone Recovery, Individual Name 2032 and thereafter Finite-Lived Intangible Asset, Expected Amortization, after Year Four Finite-Lived Intangible Asset, Expected Amortization, after Year Four Other accrued liabilities Other Accrued Liabilities, Noncurrent Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Weighted-Average Grant-Date Fair Value Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Preference shares issued (in shares) Preferred Stock, Shares Issued Cash received from employee stock purchase plan Cash Received From Employee Stock Purchase Plan Cash collected to be used to purchase Common Stock in future periods Operating Leases Operating Lease, Assets And Liabilities, Lessee [Abstract] Operating Lease, Assets And Liabilities, Lessee Under employee stock purchase plans Stock Issued During Period, Value, Employee Stock Purchase Plan Vertica Vertica [Member] Vertica Term loan quarterly repayment as percentage of principal (as a percent) Debt Instrument, Periodic Payment, Quarterly Repayment Percentage of Principal Debt Instrument, Periodic Payment, Quarterly Repayment Percentage of Principal Other assets Increase (Decrease) in Other Operating Assets Total share-based compensation expense Share-Based Payment Arrangement, Expense Repurchase of common shares (in shares) Repurchased and retired common stock (in shares) Stock Repurchased and Retired During Period, Shares Facility fee Facility Fee, Percentage Facility Fee, Percentage Amount paid Income Tax Examination, Amount Provisionally Paid Income Tax Examination, Amount Provisionally Paid Under employee stock option plans (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 Revenue recognized Contract with Customer, Liability, Revenue Recognized Subsequent Event Type [Domain] Subsequent Event Type [Domain] Accrued sales and other tax liabilities Taxes Payable, Current Revision of Prior Period [Domain] Revision of Prior Period [Domain] Forfeited or expired (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 Available-for-Sale Financial Assets AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member] Operating leases, term of contract (in years) Lessor, Operating Lease, Remaining Lease Term Lessor, Operating Lease, Remaining Lease Term Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Unrealized gain (loss) - net of tax OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, after Tax Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Entity Current Reporting Status Entity Current Reporting Status Net cash used in financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Total Shareholder Return Amount Total Shareholder Return Amount Cash flow hedge Cash Flow Hedging [Member] Other assets: Other Assets, Noncurrent [Abstract] Divestiture-related costs Divestiture Costs Divestiture Costs Adjustments to reconcile net income to net cash provided by operating activities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] Common shares eligible for issuance (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Shares Eligible for Issuance Share-based Compensation Arrangement by Share-based Payment Award, Shares Eligible for Issuance Weighted-average discount rate Weighted-Average Discount Rate [Abstract] Weighted-Average Discount Rate GUARANTEES AND CONTINGENCIES Commitments Contingencies and Guarantees [Text Block] Cash flows from financing activities: Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Property and equipment, net of accumulated depreciation of $750,779 as of September 30, 2026 and $747,892 as of June 30, 2026 Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization Severance And Miscellaneous Other Charges Severance And Miscellaneous Other Charges [Member] Severance And Miscellaneous Other Charges Interest cost Defined Benefit Plan, Interest Cost Derivative asset (Note 15) Asset Derivative Asset Intangible Asset, Finite-Lived, Class [Axis] Intangible Asset, Finite-Lived, Class [Axis] Under employee stock option plans Stock Issued During Period, Value, Stock Options Exercised Underlying Securities Award Underlying Securities Amount Comprehensive income attributable to non-controlling interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest REVENUES Revenue from Contract with Customer [Text Block] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Derivative Asset, Statement of Financial Position [Extensible Enumeration] Derivative Asset, Statement of Financial Position [Extensible Enumeration] Foreign exchange and other non-cash adjustments Restructuring Reserve, Foreign Currency Translation Gain (Loss) and Settled without Cash Restructuring Reserve, Foreign Currency Translation Gain (Loss) and Settled without Cash July 1, 2031 and beyond Contractual Obligation, to be Paid, after Year Four Contractual Obligation, to be Paid, after Year Four Other investing activities Payment for (Proceeds from) Other Investing Activity Operating leases Operating Lease, Weighted Average Discount Rate, Percent Amortization of acquired technology-based intangible assets (Note 6) Amortization of acquired technology-based intangible assets Cost, Amortization Common shares available for issuance (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant Related Party Transaction [Table] Related Party Transaction [Table] Finance leases Finance Lease, Payments Finance Lease, Payments Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Schedule of Lease Costs and Other Information Lease, Cost [Table Text Block] Effective canadian statutory income tax rate (as a percent) Effective Income Tax Rate Reconciliation At Foreign Statutory Income Tax Rate Effective Income Tax Rate Reconciliation At Foreign Statutory Income Tax Rate Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] All Trading Arrangements All Trading Arrangements [Member] Other Performance Measure, Amount Other Performance Measure, Amount Award Timing MNPI Considered Award Timing MNPI Considered [Flag] (Gain) loss reclassified into net income - net of tax expense (recovery) Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax Asia Pacific Asia Pacific [Member] Current Fiscal Year End Date Current Fiscal Year End Date Tax Year 2021 Tax Year 2021 [Member] Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Derivative [Line Items] Derivative [Line Items] Expected cost Restructuring and Related Cost, Expected Cost Restructuring Reserve [Roll Forward] Restructuring Reserve [Roll Forward] Total Total Unrecorded Unconditional Purchase Obligation Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] Dividends declared per common share (in dollars per share) Common Stock, Dividends, Per Share, Declared Entity File Number Entity File Number Gain (loss) reclassified from AOCI into income (effective portion) - cash flow hedge Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax Adjusted cost of revenues Cost of Goods and Service, Excluding Depreciation, Depletion, Amortization, And Share-Based Compensation Expense Cost of Goods and Service, Excluding Depreciation, Depletion, Amortization, And Share-Based Compensation Expense Schedule of Option Activity Share-Based Payment Arrangement, Option, Activity [Table Text Block] Weighted-Average  Exercise Price Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Measure: Measure [Axis] Aggregate intrinsic value ($’000's) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Nonvested Treasury stock (in shares) Beginning balance (in shares) Ending balance (in shares) Treasury Stock, Common, Shares Asset retirement obligations Asset Retirement Obligations, Noncurrent Schedule of Calculation of Acquired Intangibles by Asset Class Intangible Asset, Finite-Lived, Acquired [Table Text Block] Proceeds from interest on derivative instruments Payments for (Proceeds from) Hedge, Investing Activities Equity Components [Axis] Equity Components [Axis] Cash paid during the period for income taxes Income Tax Paid, after Refund Received Capitalized costs to obtain a contract, beginning balance Capitalized costs to obtain a contract, ending balance Capitalized Contract Cost, Net Entity Interactive Data Current Entity Interactive Data Current Finance lease liabilities (current) Finance Lease, Liability, Current Net (income) attributable to non-controlling interests Net (income) attributable to non-controlling interests Net Income (Loss) Attributable to Noncontrolling Interest Entity Small Business Entity Small Business Total comprehensive income attributable to OpenText Comprehensive Income (Loss), Net of Tax, Attributable to Parent Long-term deferred tax assets Disposal Group, Including Discontinued Operation, Deferred Tax Assets Weighted average amortization period Intangible Asset, Finite-Lived, Acquired, Weighted-Average Amortization Period Amounts payable in respect of restructuring and other special charges Restructuring Reserve, Noncurrent Income taxes Increase (Decrease) in Income Taxes MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Long-term income taxes payable (Note 13) Liability for Uncertainty in Income Taxes, Noncurrent Other assets (Note 7) Total Other Assets, Noncurrent 2030 Finance Lease, Liability, to be Paid, Year Three Accounts payable and accrued liabilities (Note 8) Total Current Accounts Payable And Accrued Liabilities Plus Other Accruals Current Accounts Payable And Accrued Liabilities Plus Other Accruals Document Type Document Type Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Schedule of Assets And Liabilities, Lessee Assets And Liabilities, Lessee [Table Text Block] Assets And Liabilities, Lessee Available-for-sale financial assets Available For Sale Financial Assets [Member] Available For Sale Financial Assets Exercisable Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Intrinsic Value Short-term prepaid expenses and other current assets Other Assets, Miscellaneous, Current Subsequent Event [Line Items] Subsequent Event [Line Items] Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] ITOM IT Operations Management - Product [Member] IT Operations Management - Product Local Phone Number Local Phone Number Long-term deferred revenues (Note 3) Long-term deferred revenues Contract with Customer, Liability, Noncurrent Deferred tax liabilities Disposal Group, Including Discontinued Operation, Deferred Tax Liabilities Net investment hedge Net Investment Hedging [Member] Income before income taxes Income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] 2031 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year Four Executive Category: Executive Category [Axis] Prepaid expenses and other current assets Disposal Group, Including Discontinued Operation, Prepaid and Other Assets Total finance lease receivables Finance Lease, Receivables Finance Lease, Receivables Lessor, lease renewal term (in years) Lessor, Operating Lease, Renewal Term Counterparty Name [Axis] Counterparty Name [Axis] Point in time Transferred at Point in Time [Member] LIABILITIES AND SHAREHOLDERS’ EQUITY Liabilities and Equity [Abstract] Accounts Payable and Accrued Liabilities [Abstract] Accounts Payable and Accrued Liabilities [Abstract] Income tax examination, estimate of increase to taxable income Income Tax Examination, Estimate of Increase to Taxable Income Income Tax Examination, Estimate of Increase to Taxable Income Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Unrecorded Unconditional Purchase Obligation by Category of Item Purchased [Axis] Unrecorded Unconditional Purchase Obligation by Category of Item Purchased [Axis] Deferred Share Units (DSUs) Deferred Share Units (directors) Deferred Stock Units [Member] Deferred Stock Units [Member] Reconciliation of cash, cash equivalents and restricted cash: Supplemental Cash Flow Information Supplemental Cash Flow Information [Abstract] (Gain) loss reclassified into net income - net of tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Cash paid for amounts included in the measurement of lease liabilities: Cash Paid For Amounts Included In The Measurement Of Lease Liabilities [Abstract] Cash Paid For Amounts Included In The Measurement Of Lease Liabilities PEO Name PEO Name Cash Flow Hedges Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] Income taxes paid Income Tax Paid, before Refund Received Other segment items Segment Reporting, Other Segment Item, Amount Long-Lived Asset, Class [Axis] Long-Lived Asset, Class [Axis] Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Entity Tax Identification Number Entity Tax Identification Number Unrealized gain (loss) - net of tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax Number of revenue streams (in revenue streams) Number Of Revenue Streams Number Of Revenue Streams 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] 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] BASIS OF PRESENTATION Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Total comprehensive 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] Share-based compensation expense Share-Based Payment Arrangement, Noncash Expense Total lease cost Lease, Cost Tax Period [Axis] Tax Period [Axis] Capitalized Contract Cost [Roll Forward] Capitalized Contract Cost [Roll Forward] Capitalized Contract Cost [Roll Forward] Disposal Group Name [Axis] Disposal Group Name [Axis] Income Tax Authority, Name [Domain] Income Tax Authority, Name [Domain] Employee Stock Purchase Plan Employee Stock [Member] Consultancy fees for business acquisition-related activities Related Party Transaction, Amounts of Transaction Earnings per share—basic attributable to OpenText (Note 21) (in dollars per share) Basic earnings per share attributable to OpenText (in dollars per share) Earnings Per Share, Basic Total current assets Assets, Current Insider Trading Arrangements [Line Items] Long-term debt (Note 9) Non-current portion of long-term debt Long-Term Debt, Excluding Current Maturities Short-term lease cost Short-Term Lease, Cost Accounts receivable trade, net of allowance for credit losses of $13,920 as of September 30, 2026 and $13,136 as of June 30, 2026 Accounts Receivable, after Allowance for Credit Loss, Current Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] Gain on divestiture Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal Income Tax Authority, Name [Axis] Income Tax Authority, Name [Axis] Right of use assets obtained in exchange for new lease liabilities: Right Of Use Assets Obtained In Exchange For New Lease Liabilities [Abstract] Right Of Use Assets Obtained In Exchange For New Lease Liabilities Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Cover [Abstract] Cover [Abstract] Equity Awards Adjustments Equity Awards Adjustments [Member] Hedging Relationship [Domain] Hedging Relationship [Domain] Plan Name [Axis] Plan Name [Axis] Schedule of Weighted Average Assumptions, Fair Value and Intrinsic Value Schedule of Share Based Payment Award, Valuation Assumptions, Fair Value and Intrinsic Value [Table Text Block] Schedule of Share Based Payment Award, Valuation Assumptions, Fair Value and Intrinsic Value Intangible Asset, Finite-Lived, after Accumulated Amortization [Abstract] Intangible Asset, Finite-Lived, after Accumulated Amortization [Abstract] Other miscellaneous income (expense) Other Nonoperating Income (Expense) Schedule of Share-based Compensation Costs Share-Based Payment Arrangement, Cost by Plan [Table Text Block] LONG-TERM DEBT Long-Term Debt [Text Block] Long-term income taxes recoverable (Note 13) Income Taxes Receivable, Noncurrent Schedule of Current Liabilities Schedule of Accounts Payable and Accrued Liabilities [Table Text Block] Entity Address, Country Entity Address, Country Forfeited or expired (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period General and administrative General and Administrative Expense Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Hedging Designation [Domain] Hedging Designation [Domain] Share Repurchase Program [Axis] Share Repurchase Program [Axis] Senior Secured Notes 2027 Senior Secured Notes 2027 [Member] Senior Secured Notes 2027 Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Non-contingent forward contract Foreign Exchange Forward [Member] Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Mr. P Thomas Jenkins Mr. P Thomas Jenkins [Member] Mr. P Thomas Jenkins INCOME TAXES Income Tax Disclosure [Text Block] Accounts payable - trade Accounts Payable, Current Thereafter Finance Lease, Liability, to be Paid, after Year Four Finance Lease, Liability, to be Paid, after Year Four Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Retirement Plan Type [Domain] Retirement Plan Type [Domain] Entity Filer Category Entity Filer Category Revision of Prior Period [Axis] Revision of Prior Period [Axis] Currency swap Currency Swap [Member] Total payments due Contractual Obligation, Fiscal Year Maturity [Abstract] Unrealized gain (loss) on available-for-sale financial assets: Unrealized Gain (Loss) on Available-for-Sale Financial Assets [Abstract] Unrealized Gain (Loss) on Available-for-Sale Financial Assets Long term debt obligations Long-Term Debt, Fiscal Year Maturity [Abstract] Prepaid expenses and other current assets: Prepaid Expense and Other Assets, Current [Abstract] Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Derivatives not designated as hedges Derivatives not designated as hedges: Not Designated as Hedging Instrument [Member] Unrealized gain (loss) - net of tax expense (recovery) OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), Tax OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), Tax Net income Net income Net income for the period Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Impact of foreign exchange rate changes Capitalized Contract Cost, Foreign Exchange Adjustments Capitalized Contract Cost, Foreign Exchange Adjustments Liability Derivative Liability Senior Notes Senior Notes [Member] Entity Address, Address Line One Entity Address, Address Line One Tax Years 2017, 2018, 2019, 2020, and 2021 Tax Years 2017, 2018, 2019, 2020, and 2021 [Member] Tax Years 2017, 2018, 2019, 2020, and 2021 Vested (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value ADM Application Delivery Management - Cloud Services And Subscriptions [Member] Application Delivery Management - Cloud Services And Subscriptions Provision for income taxes (Note 13) Provision for (recovery of) income taxes Income Tax Expense (Benefit) Consolidation Consolidation, Policy [Policy Text Block] Research and development Research and Development Expense (Excluding Acquired in Process Cost) ACCOUNTING POLICIES AND RECENT ACCOUNTING PRONOUNCEMENTS Accounting Standards Update and Change in Accounting Principle [Text Block] Goodwill Disposal Group, Including Discontinued Operation, Goodwill Statement [Table] Statement [Table] Contract maturity Derivative, Contract Term Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block] Impairment loss Capitalized Contract Cost, Impairment Loss Schedule of Contract Balances Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] Adjusted EBITDA Earnings Before Interest, Taxes, Depreciation, and Amortization, Adjusted, Excluding Share-Based Compensation Expense And Amortization of Acquired Technology-Based Intangible Assets Earnings Before Interest, Taxes, Depreciation, and Amortization, Adjusted, Excluding Share-Based Compensation Expense And Amortization of Acquired Technology-Based Intangible Assets Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosure [Abstract]