Schedule of Investments (Unaudited) - Treasury Bills and Money Market Fund - USD ($)		6 Months Ended		12 Months Ended
		Jun. 30, 2018		Dec. 31, 2017
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity		99.80%		95.33%
Value		$ 2,609,081,256		$ 1,839,039,728
Affiliated investments, at value		399,907,435		317,746,227
Total Investments in Securities		3,008,988,691		2,156,785,955
Investments in Securities, cost		$ 3,007,090,921		$ 2,157,140,963
Affiliated Investments [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity		13.26%		14.04%
Affiliated investments, at value		$ 399,907,435		$ 317,746,227
Affiliated Investments, at Cost		$ 398,162,297		$ 317,993,905
U.S. Treasury Bills, 1.780% due July 5, 2018 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[1],[2]	9.12%
Value	[1],[2]	$ 274,962,072
Principal Value	[1],[2]	$ 275,000,000
Investment Interest Rate		1.78%
Investment Maturity Date		Jul. 05, 2018
U.S. Treasury Bills, 1.860% due August 2, 2018 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[1],[2]	29.11%
Value	[1],[2]	$ 877,634,069
Principal Value	[1],[2]	$ 879,000,000
Investment Interest Rate		1.86%
Investment Maturity Date		Aug. 02, 2018
U.S. Treasury Bills, 1.895% due August 30, 2018 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[1],[2]	23.48%
Value	[1],[2]	$ 707,841,501
Principal Value	[1],[2]	$ 710,000,000
Investment Interest Rate		1.895%
Investment Maturity Date		Aug. 30, 2018
U.S. Treasury Bills, 2.000% due November 8, 2018 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[1],[2],[3]	24.83%
Value	[1],[2],[3]	$ 748,643,614
Principal Value	[1],[2],[3]	$ 754,000,000
Investment Interest Rate	[3]	2.00%
Investment Maturity Date	[3]	Nov. 08, 2018
Restricted for maintenance margin		$ 241,771,150
United States Treasury Obligations [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[2]	86.54%	[1]	81.29%
Value	[2]	$ 2,609,081,256	[1]	$ 1,839,039,728
Investments in Securities, cost		$ 2,608,928,624		$ 1,839,147,058
Exchange-Traded Fund [Member] | Affiliated Investments [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[4]	8.35%		11.04%
Affiliated investments, at value	[4]	$ 251,735,364		$ 249,742,548
Shares	[4]	2,372,400		2,372,400
Affiliated Investments, at Cost		$ 249,990,226		$ 249,990,226
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		4.91%	[5]	3.00%	[6]
Affiliated investments, at value		$ 148,172,071	[5]	$ 68,003,679	[6]
Shares		148,172,071	[5]	68,003,679	[6]
Investment Interest Rate		1.78%		1.15%
Affiliated Investments, at Cost		$ 148,172,071		$ 68,003,679
U.S. Treasury Bills, 1.180% due January 4, 2018 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[1],[2]			13.30%
Value	[1],[2]			$ 300,981,124
Principal Value	[1],[2]			$ 301,000,000
Investment Interest Rate				1.18%
Investment Maturity Date				Jan. 04, 2018
U.S. Treasury Bills, 1.245% due January 18, 2018 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[2]			12.77%
Value	[2]			$ 288,841,533
Principal Value	[2]			$ 289,000,000
Investment Interest Rate				1.245%
Investment Maturity Date				Jan. 18, 2018
U.S. Treasury Bills, 1.285% due February 22, 2018 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[2]			26.78%
Value	[2]			$ 605,916,505
Principal Value	[2]			$ 607,000,000
Investment Interest Rate				1.285%
Investment Maturity Date				Feb. 22, 2018
U.S. Treasury Bills, 1.285% due March 1, 2018 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[2],[7]			24.53%
Value	[2],[7]			$ 554,864,604
Principal Value	[2],[7]			$ 556,000,000
Investment Interest Rate	[7]			1.285%
Investment Maturity Date	[7]			Mar. 01, 2018
Restricted for maintenance margin				$ 199,580,000
U.S. Treasury Bills, 1.450% due June 7, 2018 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[2]			3.91%
Value	[2]			$ 88,435,962
Principal Value	[2]			$ 89,000,000
Investment Interest Rate				1.45%
Investment Maturity Date				Jun. 07, 2018

[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] 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.

[3] United States Treasury Obligations of $241,771,150 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 June 30, 2018.

[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, 2017.

[7] United States Treasury Obligations of $199,580,000 are on deposit with the Commodity Broker and held as maintenance margin for open futures contracts.