Schedule of Investments - Treasury Bills and Money Market Fund - USD ($)		Dec. 31, 2019		Dec. 31, 2018
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity		100.42%		103.49%
United States Treasury Obligations, Value		$ 123,646,647		$ 409,384,745
Affiliated Investments, Value		105,630,007		102,216,801
Investments in Securities, Value		229,276,654		511,601,546
Investments in Securities, Cost		229,340,530		511,790,491
Restricted for maintenance margin		$ 8,068,540		$ 10,614,400
Affiliated Investments [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity		46.26%		20.68%
Affiliated Investments, Value		$ 105,630,007		$ 102,216,801
Affiliated Investments, at Cost		$ 105,742,951		$ 102,405,445
US Treasury Bills, 1.520% Due February 6, 2020 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[1]	14.87%
United States Treasury Obligations, Value	[1]	$ 33,950,912
United States Treasury Obligations, Principal Value	[1]	$ 34,000,000
Investment Interest Rate	[1]	1.52%
Investment Maturity Date	[1]	Feb. 06, 2020
US Treasury Bills, 1.560% Due March 5, 2020 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[1],[2]	14.85%
United States Treasury Obligations, Value	[1],[2]	$ 33,910,899
United States Treasury Obligations, Principal Value	[1],[2]	$ 34,000,000
Investment Interest Rate	[1],[2]	1.56%
Investment Maturity Date	[1],[2]	Mar. 05, 2020
US Treasury Bills, 1.520% Due April 2, 2020 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[1],[2]	24.44%
United States Treasury Obligations, Value	[1],[2]	$ 55,784,836
United States Treasury Obligations, Principal Value	[1],[2]	$ 56,000,000
Investment Interest Rate	[1],[2]	1.52%
Investment Maturity Date	[1],[2]	Apr. 02, 2020
United States Treasury Obligations [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[1]	54.16%		82.81%
United States Treasury Obligations, Value	[1]	$ 123,646,647		$ 409,384,745
Investments in Securities, Cost		$ 123,597,579		$ 409,385,046	[1]
Exchange-Traded Fund [Member] | Affiliated Investments [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[3]	34.99%		16.15%
Affiliated Investments, Value	[3]	$ 79,893,780		$ 79,818,080
Affiliated Investments, Shares	[3]	757,000		757,000
Affiliated Investments, at Cost	[3]	$ 80,006,724		$ 80,006,724
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		11.27%	[4]	4.53%	[5]
Affiliated Investments, Value		$ 25,736,227	[4]	$ 22,398,721	[5]
Affiliated Investments, Shares		25,736,227	[4]	22,398,721	[5]
Investment Interest Rate		1.47%	[4]	2.30%	[5]
Investments in Securities, Cost		$ 25,736,227	[4]	$ 22,398,721	[5]
U.S. Treasury Bills, 2.175% due January 3, 2019 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[1]			24.68%
United States Treasury Obligations, Value	[1]			$ 121,992,392
United States Treasury Obligations, Principal Value	[1]			$ 122,000,000
Investment Interest Rate	[1]			2.175%
Investment Maturity Date	[1]			Jan. 03, 2019
U.S. Treasury Bills, 2.370% due February 28, 2019 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[1]			29.02%
United States Treasury Obligations, Value	[1]			$ 143,458,214
United States Treasury Obligations, Principal Value	[1]			$ 144,000,000
Investment Interest Rate	[1]			2.37%
Investment Maturity Date	[1]			Feb. 28, 2019
U.S. Treasury Bills, 2.465% due April 4, 2019 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[1]			10.65%
United States Treasury Obligations, Value	[1]			$ 52,672,055
United States Treasury Obligations, Principal Value	[1]			$ 53,000,000
Investment Interest Rate	[1]			2.465%
Investment Maturity Date	[1]			Apr. 04, 2019
U.S. Treasury Bills, 2.430% due May 2, 2019 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[1],[6]			18.46%
United States Treasury Obligations, Value	[1],[6]			$ 91,262,084
United States Treasury Obligations, Principal Value	[1],[6]			$ 92,000,000
Investment Interest Rate	[1],[6]			2.43%
Investment Maturity Date	[1],[6]			May 02, 2019

[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 $8,068,540 are on deposit with the Commodity Broker and held as maintenance margin for open futures contracts.

[3] Affiliated company. The security and the Fund are affiliated by having the same investment adviser. See Note 8.

[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] 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, 2018.

[6] United States Treasury Obligations of $10,614,400 are on deposit with the Commodity Broker and held as maintenance margin for open futures contracts.