Schedule of Investments - Treasury Bills and Money Market Fund - USD ($) | 12 Months Ended |
Dec. 31, 2018 | Dec. 31, 2017 |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | | 99.97% | | 97.89% | |
United States Treasury Obligations, Value | | $ 9,995,676 | | $ 17,981,134 | |
Affiliated Investments, Value | | 3,829,452 | | 2,561,161 | |
Investments in Securities, Value | | 13,825,128 | | 20,542,295 | |
Investments in Securities, Cost | | $ 13,824,819 | | $ 20,542,446 | |
U.S. Treasury Bills, 2.175% due January 3, 2019 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1],[2] | 65.08% | | | |
United States Treasury Obligations, Value | [1],[2] | $ 8,999,439 | | | |
United States Treasury Obligations, Principal Value | [1],[2] | $ 9,000,000 | | | |
Investment Interest Rate | [1] | 2.175% | | | |
Investment Maturity Date | [1] | Jan. 3, 2019 | | | |
U.S. Treasury Bills, 2.370% due February 28, 2019 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1] | 7.20% | | | |
United States Treasury Obligations, Value | [1] | $ 996,237 | | | |
United States Treasury Obligations, Principal Value | [1] | $ 1,000,000 | | | |
Investment Interest Rate | [1],[3] | 2.37% | | | |
Investment Maturity Date | [1],[3] | Feb. 28, 2019 | | | |
Restricted for maintenance margin | [1],[3] | $ 2,599,740 | | | |
United States Treasury Obligations [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1] | 72.28% | | 85.68% | |
United States Treasury Obligations, Value | [1] | $ 9,995,676 | | $ 17,981,134 | |
Investments in Securities, Cost | [1] | $ 9,995,367 | | $ 17,981,285 | |
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 | | 27.69% | [4] | 12.21% | [5] |
Affiliated Investments, Value | | $ 3,829,452 | [4] | $ 2,561,161 | [5] |
Affiliated Investments, Shares | | 3,829,452 | [4] | 2,561,161 | [5] |
Investment Interest Rate | [4] | 2.30% | | 1.15% | |
Investments in Securities, Cost | [4] | $ 3,829,452 | | $ 2,561,161 | |
U.S. Treasury Bills, 1.180% due January 4, 2018 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1] | | | 38.12% | |
United States Treasury Obligations, Value | [1] | | | $ 7,999,498 | |
United States Treasury Obligations, Principal Value | [1] | | | $ 8,000,000 | |
Investment Interest Rate | [1] | | | 1.18% | |
Investment Maturity Date | [1] | | | Jan. 4, 2018 | |
U.S. Treasury Bills, 1.285% due February 22, 2018 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1],[3] | | | 38.05% | |
United States Treasury Obligations, Value | [1],[3] | | | $ 7,985,720 | |
United States Treasury Obligations, Principal Value | [1],[3] | | | $ 8,000,000 | |
Investment Interest Rate | [1],[2] | | | 1.285% | |
Investment Maturity Date | [1],[2] | | | Feb. 22, 2018 | |
U.S. Treasury Bills, 1.285% due March 1, 2018 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1] | | | 9.51% | |
United States Treasury Obligations, Value | [1] | | | $ 1,995,916 | |
United States Treasury Obligations, Principal Value | [1] | | | $ 2,000,000 | |
Investment Interest Rate | [1] | | | 1.285% | |
Investment Maturity Date | [1] | | | Mar. 1, 2018 | |
Restricted for maintenance margin | [1] | | | $ 5,989,200 | |
| |
[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 $2,599,740 are on deposit with the Commodity Broker and held as maintenance margin for open futures contracts. | |
[3] | United States Treasury Obligations of $5,989,200 are on deposit with the Commodity Broker and held as maintenance margin for open futures contracts. | |
[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, 2018. | |
[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, 2017. | |