Investments in Affiliates - Summary of Transactions in, and Earnings from, Investments in Affiliates (Detail) - USD ($)	3 Months Ended
Mar. 31, 2023	Mar. 31, 2022
Investments In And Advances To Affiliates [Line Items]
Beginning Value	$ 68,087,284
Change in Unrealized Appreciation (Depreciation)	4,522	$ (164)
Ending Value	38,232,956
Affiliated Investments [Member] \| Money Market Mutual Fund - Invesco Government and Agency Portfolio - Institutional Class [Member]
Investments In And Advances To Affiliates [Line Items]
Beginning Value	68,087,284	31,507,548
Purchases at Cost	44,371,383	13,571,361
Proceeds from Sales	(74,225,711)	(11,600,235)
Ending Value	38,232,956	33,478,674
Dividend Income	$ 475,742	$ 5,511

Value of the investment at close of period. For investment in and advances to affiliates, if operations of any controlled companies are different in character from those of the company, group such affiliates within divisions and by type of activities.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 320
-Section S99
-Paragraph 6
-Subparagraph (SX 210.12-14(3))
-URI https://asc.fasb.org/extlink&oid=122147990&loc=d3e611322-123010

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 320
-Section S99
-Paragraph 6
-Subparagraph (SX 210.12-14(2))
-URI https://asc.fasb.org/extlink&oid=122147990&loc=d3e611322-123010

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 320
-Section S99
-Paragraph 6
-Subparagraph (SX 210.12-14(Column E))
-URI https://asc.fasb.org/extlink&oid=122147990&loc=d3e611322-123010

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Gross additions to the investment in and advance to the affiliate.

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At the close of the period, the dividends or interest included in caption 1 of the statement of operations. In addition, show as the final item the aggregate of dividends and interest included in the statement of operations in respect of investments in affiliates not held at the close of the period. The total of this column would be expected to agree with the correlative amount shown on the related statement of operations.

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Amount of unrealized gain (loss) on investment in marketable security.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
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