Investments in Affiliates -Summary of Transactions in, and Earnings from, Investments in Affiliates (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Investments in and Advances to Affiliates [Line Items]
Change in Unrealized Appreciation (Depreciation)	$ (160,819)	$ 482,703	$ (157,632)	$ (889,460)
Dividend Income	3,005,242	5,705,962	16,277,192	7,558,908
Affiliated Investments [Member]
Investments in and Advances to Affiliates [Line Items]
Investment Owned, at Fair Value, Beginning Balance	315,419,380	1,088,529,034	983,150,588	626,458,758
Purchases at Cost	280,261,284	1,449,819,215	1,056,817,293	2,776,402,734
Proceeds from Sales	(362,414,173)	(1,379,905,241)	(1,806,792,208)	(2,244,406,684)
Change in Unrealized Appreciation (Depreciation)	103,236	(124,007)	194,054	(135,807)
Investment Owned, at Fair Value, Ending Balance	233,249,135	1,158,319,001	233,249,135	1,158,319,001
Dividend Income	3,005,242	5,705,962	16,277,192	7,558,908
Affiliated Investments [Member] | Exchange-Traded Fund [Member]
Investments in and Advances to Affiliates [Line Items]
Investment Owned, at Fair Value, Beginning Balance	73,681,342	49,843,200	73,590,524	49,855,000
Purchases at Cost		23,899,275		23,899,275
Proceeds from Sales	(73,663,986)		(73,663,986)
Change in Unrealized Appreciation (Depreciation)	103,236	(124,007)	194,054	(135,807)
Realized Gain (Loss)	(120,592)		(120,592)
Investment Owned, at Fair Value, Ending Balance		73,618,468		73,618,468
Dividend Income	303,039	304,995	1,818,833	341,731
Affiliated Investments [Member] | Money Market Mutual Fund - Invesco Government & Agency Portfolio, Institutional Class [Member]
Investments in and Advances to Affiliates [Line Items]
Investment Owned, at Fair Value, Beginning Balance	241,738,038	1,038,685,834	909,560,064	576,603,758
Purchases at Cost	280,261,284	1,425,919,940	1,056,817,293	2,752,503,459
Proceeds from Sales	(288,750,187)	(1,379,905,241)	(1,733,128,222)	(2,244,406,684)
Realized Gain (Loss)	(120,592)		(120,592)
Investment Owned, at Fair Value, Ending Balance	233,249,135	1,084,700,533	233,249,135	1,084,700,533
Dividend Income	$ 2,702,203	$ 5,400,967	$ 14,458,359	$ 7,217,177