Schedule of Investments (Unaudited) - Treasury Bills and Affiliated Investments - USD ($) | 3 Months Ended | 12 Months Ended |
Mar. 31, 2019 | Dec. 31, 2018 |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | | 100.66% | | 99.86% | |
United States Treasury Obligations, Value | | $ 285,502,464 | | $ 227,905,176 | |
Affiliated Investments, Value | | 17,132,124 | | 33,302,539 | |
Investments in Securities, Value | | 302,634,588 | | 261,207,715 | |
Investments in Securities, Cost | | $ 302,622,860 | | $ 261,202,445 | |
Affiliated Investments [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | | 5.70% | | 12.73% | |
Affiliated Investments, Value | | $ 17,132,124 | | $ 33,302,539 | |
Affiliated Investments, at Cost | | $ 17,126,633 | | $ 33,299,423 | |
U.S. Treasury Bills, 2.465% due April 4, 2019 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1] | 33.25% | | 37.99% | [2] |
United States Treasury Obligations, Value | [1] | $ 99,980,365 | | $ 99,381,236 | [2] |
United States Treasury Obligations, Principal Value | [1] | $ 100,000,000 | | $ 100,000,000 | [2] |
Investment Interest Rate | [1] | 2.465% | | 2.465% | [2] |
Investment Maturity Date | [1] | Apr. 4, 2019 | | Apr. 4, 2019 | [2] |
U.S. Treasury Bills, 2.470% due April 23, 2019 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1] | 21.26% | | | |
United States Treasury Obligations, Value | [1] | $ 63,906,746 | | | |
United States Treasury Obligations, Principal Value | [1] | $ 64,000,000 | | | |
Investment Interest Rate | [1] | 2.47% | | | |
Investment Maturity Date | [1] | Apr. 23, 2019 | | | |
U.S. Treasury Bills, 2.375% due May 2, 2019 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1],[3] | 30.54% | | | |
United States Treasury Obligations, Value | [1],[3] | $ 91,814,323 | | | |
United States Treasury Obligations, Principal Value | [1],[3] | $ 92,000,000 | | | |
Investment Interest Rate | [1],[3] | 2.375% | | | |
Investment Maturity Date | [1],[3] | May 2, 2019 | | | |
Restricted for maintenance margin | | $ 48,597,730 | | | |
U.S. Treasury Bills, 2.470% due July 11, 2019 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1] | 9.91% | | | |
United States Treasury Obligations, Value | [1] | $ 29,801,030 | | | |
United States Treasury Obligations, Principal Value | [1] | $ 30,000,000 | | | |
Investment Interest Rate | [1] | 2.47% | | | |
Investment Maturity Date | [1] | Jul. 11, 2019 | | | |
Exchange-Traded Fund [Member] | Affiliated Investments [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [4] | 1.67% | | 1.91% | |
Affiliated Investments, Value | [4] | $ 5,010,775 | | $ 5,008,400 | |
Affiliated Investments, Shares | [4] | 47,500 | | 47,500 | |
Affiliated Investments, at Cost | [4] | $ 5,005,284 | | $ 5,005,284 | |
United States Treasury Obligations [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1] | 94.96% | | 87.13% | |
United States Treasury Obligations, Value | [1] | $ 285,502,464 | | $ 227,905,176 | |
Investments in Securities, Cost | [1] | $ 285,496,227 | | $ 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 | | 4.03% | [5] | 10.82% | [6] |
Affiliated Investments, Value | | $ 12,121,349 | [5] | $ 28,294,139 | [6] |
Affiliated Investments, Shares | | 12,121,349 | [5] | 28,294,139 | [6] |
Investment Interest Rate | | 2.33% | [5] | 2.30% | [1] |
Affiliated Investments, at Cost | | $ 12,121,349 | [5] | $ 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, 2.430% due May 2, 2019 [Member] | | | | | |
Schedule of Investments [Line Items] | | | | | |
Percentage of Shareholders' Equity | [1],[2] | | | 16.31% | |
United States Treasury Obligations, Value | [1],[2] | | | $ 42,655,104 | |
United States Treasury Obligations, Principal Value | [1],[2] | | | $ 43,000,000 | |
Investment Interest Rate | [1],[2] | | | 2.43% | |
Investment Maturity Date | [1],[2] | | | 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 $44,349,600 are on deposit with the Commodity Broker and held as maintenance margin for open futures contracts. | |
[3] | United States Treasury Obligations of $48,597,730 are on deposit with the Commodity Broker and held as maintenance margin for open futures contracts. | |
[4] | Affiliated company. The security and the Fund are affiliated by having the same investment adviser. See Note 8. | |
[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 March 31, 2019. | |
[6] | 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. | |