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 | | 99.91% | | 101.51% | |
United States Treasury Obligations, Value | | $ 145,770,879 | | $ 88,687,386 | |
Affiliated Investments, Value | | 9,332,861 | | 7,355,184 | |
Investments in Securities, Value | | 155,103,740 | | 96,042,570 | |
Investments in Securities, Cost | | $ 155,061,855 | | $ 96,050,614 | |
U.S. Treasury Bills, 2.375% due July 11, 2019 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1],[2] | 37.34% | | | |
United States Treasury Obligations, Value | [1],[2] | $ 57,969,026 | | | |
United States Treasury Obligations, Principal Value | [1],[2] | $ 58,000,000 | | | |
Investment Interest Rate | [1] | 2.375% | | | |
Investment Maturity Date | [1] | Jul. 11, 2019 | | | |
Restricted for maintenance margin | | $ 16,190,280 | | | |
U.S. Treasury Bills, 2.385% due August 1, 2019 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1] | 12.09% | | | |
United States Treasury Obligations, Value | [1] | $ 18,767,541 | | | |
United States Treasury Obligations, Principal Value | [1] | $ 18,800,000 | | | |
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] | 9.64% | | | |
United States Treasury Obligations, Value | [1] | $ 14,960,860 | | | |
United States Treasury Obligations, Principal Value | [1] | $ 15,000,000 | | | |
Investment Interest Rate | [1] | 2.36% | | | |
Investment Maturity Date | [1] | Aug. 15, 2019 | | | |
U.S. Treasury Bills, 2.240% due September 12, 2019 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1] | 34.83% | | | |
United States Treasury Obligations, Value | [1] | $ 54,073,452 | | | |
United States Treasury Obligations, Principal Value | [1] | $ 54,300,000 | | | |
Investment Interest Rate | [1],[2] | 2.24% | | | |
Investment Maturity Date | [1],[2] | Sep. 12, 2019 | | | |
United States Treasury Obligations [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | | 93.90% | [1] | 93.74% | [3] |
United States Treasury Obligations, Value | | $ 145,770,879 | [1] | $ 88,687,386 | [3] |
Investments in Securities, Cost | | $ 145,728,994 | [1] | $ 88,695,430 | [3] |
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 | | 6.01% | [4] | 7.77% | [5] |
Affiliated Investments, Value | | $ 9,332,861 | [4] | $ 7,355,184 | [5] |
Affiliated Investments, Shares | | 9,332,861 | [4] | 7,355,184 | [5] |
Investment Interest Rate | | 2.26% | [1],[4] | 2.30% | [3],[5] |
Investments in Securities, Cost | | $ 9,332,861 | [4] | $ 7,355,184 | [5] |
U.S. Treasury Bills, 2.175% due January 3, 2019 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [3] | | | 19.03% | |
United States Treasury Obligations, Value | [3] | | | $ 17,998,877 | |
United States Treasury Obligations, Principal Value | [3] | | | $ 18,000,000 | |
Investment Interest Rate | [3] | | | 2.175% | |
Investment Maturity Date | [3] | | | Jan. 3, 2019 | |
U.S. Treasury Bills, 2.370% due February 28, 2019 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [3],[6] | | | 61.07% | |
United States Treasury Obligations, Value | [3],[6] | | | $ 57,781,781 | |
United States Treasury Obligations, Principal Value | [3],[6] | | | $ 58,000,000 | |
Investment Interest Rate | [3],[6] | | | 2.37% | |
Investment Maturity Date | [3],[6] | | | Feb. 28, 2019 | |
Restricted for maintenance margin | [6] | | | $ 11,157,440 | |
U.S. Treasury Bills, 2.465% due April 4, 2019 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [3] | | | 6.30% | |
United States Treasury Obligations, Value | [3] | | | $ 5,962,874 | |
United States Treasury Obligations, Principal Value | [3] | | | $ 6,000,000 | |
Investment Interest Rate | [3] | | | 2.465% | |
Investment Maturity Date | [3] | | | Apr. 4, 2019 | |
U.S. Treasury Bills, 2.430% due May 2, 2019 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [3] | | | 7.34% | |
United States Treasury Obligations, Value | [3] | | | $ 6,943,854 | |
United States Treasury Obligations, Principal Value | [3] | | | $ 7,000,000 | |
Investment Interest Rate | [3] | | | 2.43% | |
Investment Maturity Date | [3] | | | May 2, 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 $16,190,280 are on deposit with the Commodity Broker and held as maintenance margin for open futures contracts. | |
[3] | 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 | |
[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 $11,157,440 are on deposit with the Commodity Broker and held as maintenance margin for open futures contracts. | |