Schedule of Investments (Unaudited) - Treasury Bills and Money Market Fund - USD ($)		Mar. 31, 2020		Dec. 31, 2019
Schedule Of Investments [Line Items]
Percentage of Shareholders' Equity		99.51%		99.94%
United States Treasury Obligations, Value		$ 12,998,662		$ 17,974,012
Affiliated Investments, Value		4,914,839		6,356,398
Investments in Securities, Value		17,913,501		24,330,410
Investments in Securities, Cost		$ 17,883,769		$ 24,327,638
U.S. Treasury Bills, 1.505% due May 28, 2020 [Member]
Schedule Of Investments [Line Items]
Percentage of Shareholders' Equity	[1],[2]	72.21%
United States Treasury Obligations, Value	[1],[2]	$ 12,998,662
United States Treasury Obligations, Principal Value	[1],[2]	$ 13,000,000
Investment Interest Rate	[2]	1.505%
Restricted for maintenance margin		$ 999,900
Investment Maturity Date		May 28, 2020
United States Treasury Obligations [Member]
Schedule Of Investments [Line Items]
Percentage of Shareholders' Equity	[1]	72.21%		73.83%
United States Treasury Obligations, Value	[1]	$ 12,998,662		$ 17,974,012
Investments in Securities, Cost	[1]	$ 12,968,930		$ 17,971,240
Money Market Mutual Fund - Invesco Premier U.S. Government Money Portfolio- Institutional Class [Member] | Affiliated Investments [Member]
Schedule Of Investments [Line Items]
Percentage of Shareholders' Equity		27.30%	[3]	26.11%	[4]
Affiliated Investments, Value		$ 4,914,839	[3]	$ 6,356,398	[4]
Affiliated Investments, Shares		4,914,839	[3]	6,356,398	[4]
Affiliated Investments, at Cost		$ 4,914,839	[3]	$ 6,356,398	[4]
Investment Interest Rate		0.54%	[3]	1.47%	[4]
U.S. Treasury Bills, 1.520% due February 6, 2020 [Member]
Schedule Of Investments [Line Items]
Percentage of Shareholders' Equity	[1],[5]			73.83%
United States Treasury Obligations, Value	[1],[5]			$ 17,974,012
United States Treasury Obligations, Principal Value	[1],[5]			$ 18,000,000
Investment Interest Rate	[5]			1.52%
Restricted for maintenance margin				$ 998,500
Investment Maturity Date	[5]			Feb. 06, 2020

[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.

[2] United States Treasury Obligations of $999,900 are on deposit with the Commodity Broker and held as maintenance margin for open futures contracts.

[3] The security and the Fund are advised by wholly-owned subsidiaries of Invesco Ltd. and are therefore considered to be affiliated. The rate shown is the 7-day SEC standardized yield as of March 31, 2020.

[4] The security and the Fund are advised by wholly-owned subsidiaries of Invesco Ltd. and are therefore considered to be affiliated. The rate shown is the 7-day SEC standardized yield as of December 31, 2019.

[5] United States Treasury Obligations of $998,500 are on deposit with the Commodity Broker and held as maintenance margin for open futures contracts.