Additional Valuation Information - Summary of the Tiered Valuation Input Levels (Detail) - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
United States Treasury Obligations	$ 111,993,384	$ 123,646,647
Exchange-Traded Fund	80,385,830	79,893,780
Money Market Mutual Fund	764,794,582	25,736,227
Total Investments in Securities	957,173,796	229,276,654
Commodity Futures Contracts, Unrealized Appreciation (Depreciation)	(7,570,162)	(1,815,323)
Total Investments	949,603,634	227,461,331
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Exchange-Traded Fund	80,385,830	79,893,780
Money Market Mutual Fund	764,794,582	25,736,227
Total Investments in Securities	845,180,412	105,630,007
Commodity Futures Contracts, Unrealized Appreciation (Depreciation)	(7,570,162)	(1,815,323)
Total Investments	837,610,250	103,814,684
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
United States Treasury Obligations	111,993,384	123,646,647
Total Investments in Securities	111,993,384	123,646,647
Total Investments	$ 111,993,384	$ 123,646,647