Summary of Significant Accounting Policies - Summary of valuation techniques and observable inputs can vary by investment (Detail) - USD ($) $ in Thousands |
Jun. 30, 2026 |
Dec. 31, 2025 |
Jun. 30, 2025 |
Dec. 31, 2024 |
|---|---|---|---|---|
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||||
| Investment in ETC | $ 75,300 | $ 126,004 | $ 186,564 | $ 283,055 |
| Level 1 | ||||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||||
| Investment in ETC | 75,300 | 126,004 | ||
| Level 2 | ||||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||||
| Investment in ETC | 0 | 0 | ||
| Level 3 | ||||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||||
| Investment in ETC | $ 0 | $ 0 |
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Fair value of investment in security owned. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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