Class of Stock [Axis] Total Assets Total Liabilities Net Assets Net assets at end of period (in Dollars) Consolidated Entities [Axis] Total Investment Income and Expenses Allocated from ISQ Open Infrastructure Company LLC - Series II Net Investment Income and Expenses Allocated from ISQ Open Infrastructure Company LLC - Series II Net investment income and expenses allocated from ISQ Open Infrastructure Company LLC – Series II Total Expenses Net Expenses Net Investment Income (Loss) Income (loss) before taxes Net Realized and Unrealized Gain (Loss) on Investments Total Income Balance Balance Equity Components [Axis] Net cash used in operating activities Net cash provided by financing activities Net increase (decrease) in cash Cash, beginning of period Cash, end of period Cash and cash equivalents Cost, Total Equity Investments Fair Value, Total Equity Investments Fair Value as a Percentage of Net Assets, Total Equity Investments Cost, Total Investments, at fair value Fair Value, Total Investments, at fair value Investment at fair value Investments fair value Fair Value as a Percentage of Net Assets, Total Investments, at fair value Cost, Total Cash Equivalents Cash equivalents (in Dollars) Fair Value, Total Cash Equivalents Fair Value as a Percentage of Net Assets, Total Cash Equivalents Cost, Total Investments and Cash Equivalent Fair Value, Total Investments and Cash Equivalent Fair Value as a Percentage of Net Assets, Total Investments and Cash Equivalent Statistical Measurement [Axis] Related and Nonrelated Parties [Axis] Shares Outstanding Shares Outstanding Shares outstanding (in Shares) Shares outstanding at end of period (in Shares) Net asset value at beginning of period Net asset value at end of period Net asset value per share (in Dollars per share) Total expenses before expense support Total expenses after expense support Total return Total return Total Return attributable Subsequent Events [Abstract] Asset Class [Axis] Derivative Instrument [Axis] Fair Value Hierarchy and NAV [Axis] Balance as of December 31, 2025 Balance as of June 30, 2026 Currency [Axis] Total income (loss) before income taxes Deferred Federal and State and Local Income Tax Current Federal and State and Local Income Tax Total Income Tax Provision (Benefit) Income tax expense (benefit) Assets Due from Manager - Expense Support Due from manager Distribution receivable from ISQ Open Infrastructure Company LLC - Series II Deferred offering costs Liabilities Distribution payable Professional fees payable Organizational costs payable Offering costs payable Accounts payable & accrued expenses Commitments and Contingencies Net Asset Value Per Share F-STE Shares F-DTE Shares F-ITE Shares F-JTE Shares STE Shares DTE Shares ITE Shares JTE Shares ETE Shares Investments Cost Deferred financing costs Prepaid expenses and other assets Prepaid income tax Deferred tax liability Servicing fees payable Performance participation allocation payable Promissory Notes (net of debt issuance costs of $136,150 and $167,226, respectively) Net of debt issuance costs Management fees payable Interest payable Current income tax payable Current Tax Payable Derivative liabilities at fair value Loan payable Outstanding amount Net Asset Value Per Share F-STE Shares F-DTE Shares F-ITE Shares F-JTE Shares STE Shares DTE Shares ITE Shares JTE Shares ETE Shares F-S Shares F-I Shares F-J Shares I Shares J Shares E Shares Investment Income and Expenses Allocated from ISQ Open Infrastructure Company LLC - Series II Dividend income Interest income (net of tax withholding of $54,535 and $0, respectively) Net of tax withholding Professional fees Interest and loan related fees Management fees Amortization of deferred offering costs Broken deal expenses Travel and entertainment expenses Other expenses Performance participation allocation Servicing fees Expenses Expenses Professional fees Amortization of deferred offering costs Organizational costs Organizational expenses cost Net Realized and Unrealized Gain (Loss) on Investments Net Change in Unrealized Gain (Loss) on investment Net of deferred taxes Net of current taxes Net change in unrealized gain (loss) on derivative investments Net change in unrealized (gain) loss on derivative investments Realized gain (loss) Net change in unrealized gain (loss) on foreign currency translation Net Increase (Decrease) in Net Assets Resulting from Operations Net increase (decrease) in net assets resulting from operations Net income (loss) Other expenses Income Consideration from the issuance of shares Reinvestment of distributions Net increase (decrease) in net assets resulting from capital activity Net investment gain (loss) Net change in unrealized appreciation (depreciation) Accrued service fees allocated from ISQ Open Infrastructure Company LLC - Series II Reallocation of unrealized gain (loss) Accrued service fees Accrued service fees Accrued service fees Cash flows from operating activities Adjustments to reconcile net increase in net assets resulting from operations to net cash used in operating activities: Adjustments to reconcile net increase (decrease) in net assets resulting from operations to net cash used in operating activities: Net (increase) decrease in operating assets: Net increase (decrease) in operating liabilities: Accounts payable & accrued expenses Professional fees payable Organizational costs payable Cash flows from financing activities Capital contributions Contribution capital Contributed capital Supplemental disclosure of non-cash financing activities Reinvestment of distributions Amortization/accretion of servicing fees Amortization of debt issuance costs Amortization of debt financing costs Amortization of deferred financing costs Net (increase) decrease in operating assets: Performance participation allocation payable Management fees payable Current income tax payable Interest payable Borrowings from loans Supplemental disclosure of cash flow information Cash paid for income taxes Cash paid for interest Debt Investments North America Interest Rate Maturity Date Type of Investment Industry Principal Investments affiliates Cost Fair Value Fair Value as a Percentage of Net Assets Owned percentage of net assets Europe Equity Investments North America Asset Ownership % of Investment Foreign Currency Contracts Notional Amount Cost, Total Derivative Investments, at fair value Fair Value as a Percentage of Net Assets Fair Value, Total Derivative Investments, at fair value Cash Equivalents Money Market Fund Shares (in Shares) Debt Investments