v3.26.1
Fair Value Measurement and Disclosures - Schedule of Quantitative Measures Used to Determine the Fair Values (Details) - ISQ Open Infrastructure Company LLC - Series II [Member] - USD ($)
 6 Months Ended 9 Months Ended
Jun. 30, 2026
Dec. 31, 2025
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Valuation Methodology & Inputs Discounted Cash Flow Discounted Cash Flow
Unobservable Input Exit Multiple Exit Multiple
Weighted Average 8.50% 7.40%
Impact to Valuation from an Increase in Input Increase Increase
Equity Investments [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value $ 294,005,843 $ 167,053,547
Valuation Methodology & Inputs Discounted Cash Flow Discounted Cash Flow
Unobservable Input Discount Rate Discount Rate
Weighted Average 12.90% 12.30%
Impact to Valuation from an Increase in Input Decrease Decrease
Debt Investments [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Fair Value $ 13,819,312 $ 16,126,398
Valuation Methodology & Inputs Discounted Cash Flow Discounted Cash Flow
Unobservable Input Discount Rate Discount Rate
Weighted Average 10.30% 10.40%
Impact to Valuation from an Increase in Input Decrease Decrease
Minimum [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Range 5.00% 5.00%
Minimum [Member] | Equity Investments [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Range 11.50% 11.50%
Minimum [Member] | Debt Investments [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Range 9.50% 9.00%
Maximum [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Range 16.50% 15.00%
Maximum [Member] | Equity Investments [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Range 17.30% 17.30%
Maximum [Member] | Debt Investments [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Range 10.80% 13.00%