Investments in Affiliates - Additional Information (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Investments In And Advances To Affiliates [Line Items]
Treasury obligation measurement maximum maturity period	12 months
United States Treasury Obligations, Value	$ 35,996,595	$ 54,989,124
United States Treasury Obligations [Member]
Investments In And Advances To Affiliates [Line Items]
United States Treasury Obligations, Value	$ 35,996,595	$ 54,989,124	[1]
United States Treasury Obligations [Member] | Affiliated Investments [Member]
Investments In And Advances To Affiliates [Line Items]
Treasury obligation measurement minimum maturity period	1 month
Treasury obligation measurement maximum maturity period	12 months
Minimum [Member] | United States Treasury Obligations [Member] | Affiliated Investments [Member]
Investments In And Advances To Affiliates [Line Items]
United States Treasury Obligations, Value	$ 300,000,000

[1] Security may be traded on a discount basis. The interest rate shown represents the discount rate at the most recent auction date of the security prior to period end.