Schedule of Investments (Unaudited) - Treasury Bills and Money Market Fund - USD ($) | 6 Months Ended | 12 Months Ended |
Jun. 30, 2019 | Dec. 31, 2018 |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | | 99.89% | | 100.99% | |
United States Treasury Obligations, Value | | $ 109,752,708 | | $ 101,406,388 | |
Affiliated investments, at value and cost | | 6,508,712 | | 8,547,404 | |
Investments in Securities, Value | | 116,261,420 | | 109,953,792 | |
Investments in Securities, Cost | | $ 116,224,996 | | $ 109,942,077 | |
U.S. Treasury Bills, 2.385% due August 1, 2019 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1] | 66.98% | | | |
United States Treasury Obligations, Value | [1] | $ 77,965,158 | | | |
United States Treasury Obligations, Principal Value | [1] | $ 78,100,000 | | | |
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] | 9.43% | | | |
United States Treasury Obligations, Value | [1],[2] | $ 10,971,297 | | | |
United States Treasury Obligations, Principal Value | [1],[2] | $ 11,000,000 | | | |
Investment Interest Rate | [1],[2] | 2.36% | | | |
Investment Maturity Date | [1],[2] | Aug. 15, 2019 | | | |
Restricted for maintenance margin | | $ 14,058,380 | | | |
U.S. Treasury Bills, 2.300% due September 5, 2019 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1] | 8.56% | | | |
United States Treasury Obligations, Value | [1] | $ 9,961,729 | | | |
United States Treasury Obligations, Principal Value | [1] | $ 10,000,000 | | | |
Investment Interest Rate | [1] | 2.30% | | | |
Investment Maturity Date | [1] | Sep. 5, 2019 | | | |
U.S. Treasury Bills, 2.240% due September 12, 2019 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1],[2] | 9.33% | | | |
United States Treasury Obligations, Value | [1],[2] | $ 10,854,524 | | | |
United States Treasury Obligations, Principal Value | [1],[2] | $ 10,900,000 | | | |
Investment Interest Rate | [1],[2] | 2.24% | | | |
Investment Maturity Date | [1],[2] | Sep. 12, 2019 | | | |
Restricted for maintenance margin | | $ 14,058,380 | | | |
United States Treasury Obligations [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1] | 94.30% | | 93.14% | |
United States Treasury Obligations, Value | [1] | $ 109,752,708 | | $ 101,406,388 | |
Investments in Securities, Cost | | $ 109,716,284 | | $ 101,394,673 | |
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 | | 5.59% | [3] | 7.85% | [4] |
Affiliated investments, at value and cost | | $ 6,508,712 | [3] | $ 8,547,404 | [4] |
Affiliated Investments, Shares | | 6,508,712 | [3] | 8,547,404 | [4] |
Investment Interest Rate | | 2.26% | [3] | 2.30% | [4] |
Investments in Securities, Cost | | $ 6,508,712 | [3] | $ 8,547,404 | [4] |
U.S. Treasury Bills, 2.175% due January 3, 2019 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1] | | | 22.96% | |
United States Treasury Obligations, Value | [1] | | | $ 24,998,441 | |
United States Treasury Obligations, Principal Value | [1] | | | $ 25,000,000 | |
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] | | | 5.49% | |
United States Treasury Obligations, Value | [1] | | | $ 5,977,426 | |
United States Treasury Obligations, Principal Value | [1] | | | $ 6,000,000 | |
Investment Interest Rate | [1] | | | 2.37% | |
Investment Maturity Date | [1] | | | Feb. 28, 2019 | |
U.S. Treasury Bills, 2.430% due May 2, 2019 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1],[5] | | | 64.69% | |
United States Treasury Obligations, Value | [1],[5] | | | $ 70,430,521 | |
United States Treasury Obligations, Principal Value | [1],[5] | | | $ 71,000,000 | |
Investment Interest Rate | [1],[5] | | | 2.43% | |
Investment Maturity Date | [1],[5] | | | May 2, 2019 | |
Restricted for maintenance margin | | | | $ 12,003,200 | |
| |
[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 $14,058,380 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 June 30, 2019. | |
[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] | United States Treasury Obligations of $12,003,200 are on deposit with the Commodity Broker and held as maintenance margin for open futures contracts. | |