Schedule of Investments (Unaudited) - Treasury Bills and Affiliated Investments - USD ($) | 6 Months Ended | 12 Months Ended |
Jun. 30, 2019 | Dec. 31, 2018 |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | | 101.63% | | 99.86% | |
United States Treasury Obligations, Value | | $ 258,418,472 | | $ 227,905,176 | |
Affiliated Investments, Value | | 31,805,863 | | 33,302,539 | |
Investments in Securities, Value | | 290,224,335 | | 261,207,715 | |
Investments in Securities, Cost | | $ 290,101,314 | | $ 261,202,445 | |
Affiliated Investments [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | | 11.14% | | 12.73% | |
Affiliated Investments, Value | | $ 31,805,863 | | $ 33,302,539 | |
Affiliated Investments, at Cost | | $ 31,795,384 | | $ 33,299,423 | |
U.S. Treasury Bills, 2.385% due August 1, 2019 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1] | 22.37% | | | |
United States Treasury Obligations, Value | [1] | $ 63,889,502 | | | |
United States Treasury Obligations, Principal Value | [1] | $ 64,000,000 | | | |
Investment Interest Rate | [1] | 2.385% | | | |
Investment Maturity Date | [1] | Aug. 1, 2019 | | | |
U.S. Treasury Bills, 2.360% due August 15, 2019 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1],[2] | 23.75% | | | |
United States Treasury Obligations, Value | [1],[2] | $ 67,822,562 | | | |
United States Treasury Obligations, Principal Value | [1],[2] | $ 68,000,000 | | | |
Investment Interest Rate | [1],[2] | 2.36% | | | |
Investment Maturity Date | [1],[2] | Aug. 15, 2019 | | | |
Restricted for maintenance margin | | $ 48,495,460 | | | |
U.S. Treasury Bills, 2.240% due September 12, 2019 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1] | 41.76% | | | |
United States Treasury Obligations, Value | [1] | $ 119,250,385 | | | |
United States Treasury Obligations, Principal Value | [1] | $ 119,750,000 | | | |
Investment Interest Rate | [1] | 2.24% | | | |
Investment Maturity Date | [1] | Sep. 12, 2019 | | | |
U.S. Treasury Bills, 2.395% due October 10, 2019 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1] | 2.61% | | | |
United States Treasury Obligations, Value | [1] | $ 7,456,023 | | | |
United States Treasury Obligations, Principal Value | [1] | $ 7,500,000 | | | |
Investment Interest Rate | [1] | 2.21% | | | |
Investment Maturity Date | [1] | Oct. 10, 2019 | | | |
Exchange-Traded Fund [Member] | Affiliated Investments [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [3] | | | 1.91% | |
Affiliated Investments, Value | | $ 5,015,763 | | $ 5,008,400 | [3] |
Affiliated Investments, Shares | [3] | | | 47,500 | |
Affiliated Investments, at Cost | [3] | $ 5,005,284 | | $ 5,005,284 | |
United States Treasury Obligations [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1] | 90.49% | | 87.13% | |
United States Treasury Obligations, Value | [1] | $ 258,418,472 | | $ 227,905,176 | |
Investments in Securities, Cost | [1] | $ 258,305,930 | | $ 227,903,022 | |
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 | | 9.38% | [4] | 10.82% | [5] |
Affiliated Investments, Value | | $ 26,790,100 | [4] | $ 28,294,139 | [5] |
Affiliated Investments, Shares | | 26,790,100 | [4] | 28,294,139 | [5] |
Investment Interest Rate | | 2.26% | [4] | 2.30% | [1] |
Affiliated Investments, at Cost | | $ 26,790,100 | [4] | $ 28,294,139 | [1] |
U.S. Treasury Bills, 2.175% due January 3, 2019 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1] | | | 19.88% | |
United States Treasury Obligations, Value | [1] | | | $ 51,996,757 | |
United States Treasury Obligations, Principal Value | [1] | | | $ 52,000,000 | |
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] | | | 12.95% | |
United States Treasury Obligations, Value | [1] | | | $ 33,872,079 | |
United States Treasury Obligations, Principal Value | [1] | | | $ 34,000,000 | |
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],[6] | | | 37.99% | |
United States Treasury Obligations, Value | [1],[6] | | | $ 99,381,236 | |
United States Treasury Obligations, Principal Value | [1],[6] | | | $ 100,000,000 | |
Investment Interest Rate | [1],[6] | | | 2.465% | |
Investment Maturity Date | [1],[6] | | | Apr. 4, 2019 | |
U.S. Treasury Bills, 2.430% due May 2, 2019 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1],[6] | | | 16.31% | |
United States Treasury Obligations, Value | [1],[6] | | | $ 42,655,104 | |
United States Treasury Obligations, Principal Value | [1],[6] | | | $ 43,000,000 | |
Investment Interest Rate | [1],[6] | | | 2.43% | |
Investment Maturity Date | [1],[6] | | | May 2, 2019 | |
Restricted for maintenance margin | | | | $ 44,349,600 | |
| |
[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 $48,495,460 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 June 30, 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 $44,349,600 are on deposit with the Commodity Broker and held as maintenance margin for open futures contracts. | |