Statements of Assets and Liabilities (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024
Statement of Financial Position [Abstract]
Investment in ETC, at fair value (cost $87,209 and $89,416 as of December 31, 2023 and 2022, respectively)	$ 82,955	$ 85,055
Common stock, shares authorized, unlimited	Unlimited	Unlimited
Number of authorized shares not disclosed	true	true

Cost of the investment.

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+ Details