Additional Valuation Information - Summary of the Tiered Valuation Input Levels (Detail) - USD ($)	Sep. 30, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
United States Treasury Obligations	$ 369,962,827	$ 664,863,392
Exchange-Traded Fund	181,052,052	250,383,096
Money Market Mutual Fund	467,764,087	517,499,491
Total Investments in Securities	1,018,778,966	1,432,745,979
Commodity Futures Contracts, Appreciation	75,614,015	67,605,844
Commodity Futures Contracts, Depreciation	(75,157,786)	(19,911,449)
Commodity Futures Contracts	456,229	47,694,395
Total Investments	1,019,235,195	1,480,440,374
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Exchange-Traded Fund	181,052,052	250,383,096
Money Market Mutual Fund	467,764,087	517,499,491
Total Investments in Securities	648,816,139	767,882,587
Commodity Futures Contracts, Appreciation	75,614,015	67,605,844
Commodity Futures Contracts, Depreciation	(75,157,786)	(19,911,449)
Commodity Futures Contracts	456,229	47,694,395
Total Investments	649,272,368	815,576,982
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
United States Treasury Obligations	369,962,827	664,863,392
Total Investments in Securities	369,962,827	664,863,392
Total Investments	$ 369,962,827	$ 664,863,392