Fair Value of ETC - Summary of changes in quantity of ETC and the respective fair value (Detail) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2024 USD ($) ETC	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) ETC	Jun. 30, 2023 USD ($) ETC	Dec. 31, 2023 USD ($) ETC
Fair Value Disclosures [Abstract]
Investment Owned, Balance | ETC			11,548,776.1723	11,841,144.97143656	11,841,144.97143656
ETC contributed | ETC			0		0
ETC distributed for Sponsor's Fee, related party | ETC			(142,686.96650283)		(292,368.79913656)
Net change in unrealized (depreciation) appreciation on investment in ETC | ETC			0		0
Net realized gain on investment in ETC | ETC			0		0
Investment Owned, Balance | ETC	11,406,089.20579717		11,406,089.20579717		11,548,776.1723
Investment Owned, at Fair Value | $			$ 253,958	$ 187,327	$ 187,327
ETC contributed | $			0		0
ETC distributed for Sponsor's Fee, related party | $			(3,964)		(5,476)
Net change in unrealized appreciation on investment in ETC | $	$ (121,879)	$ (12,304)	15,847	44,288	68,838
Net realized gain on investment in ETC | $	1,436	$ 812	2,886	$ 1,774	3,269
Investment Owned, at Fair Value | $	$ 268,727		$ 268,727		$ 253,958