Summary of Significant Accounting Policies - Schedule of Distributions per General Share and Share in Total (Detail) - USD ($)	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
General Shares [Member]
Summary Of Significant Accounting Policies [Line Items]
Distribution per share	$ 0.53553	$ 0.89039	$ 0.96078
Distributions paid	$ 21	$ 36	$ 38
Shares [Member]
Summary Of Significant Accounting Policies [Line Items]
Distribution per share	$ 0.53553	$ 0.89039	$ 0.96078
Distributions paid	$ 4,070,028	$ 2,715,689	$ 3,266,652

The total amount of dividends declared in the period for each class of stock and the contractual amount of dividends (or interest on participating income bonds) that must be paid for the period (for example, unpaid cumulative dividends). Dividends declared in the current period do not include dividends declared in respect of prior-period unpaid cumulative dividends. Preferred dividends that are cumulative only if earned are deducted only to the extent that they are earned.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 60B
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482689/260-10-45-60B

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration