Statements of Assets and Liabilities (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Investment in ETC, at fair value (cost $86,131 and $87,209 as of June 30, 2024 and December 31, 2023, respectively)	$ 86,131	$ 87,209