Schedule of Investments (Unaudited) - Treasury Bills and Money Market Fund - USD ($)		6 Months Ended		12 Months Ended
		Jun. 30, 2017		Dec. 31, 2016
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity		100.22%
Value		$ 18,984,562		$ 23,853,157
Affiliated Investments, at Value		1,591,026
Total Investments		20,575,588		23,853,157
Investments, cost		$ 20,575,247		$ 23,852,335
U.S. Treasury Bills, 0.840% due July 6, 2017 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity		4.87%
Value		$ 999,937
Principal Value		$ 1,000,000
Investment Interest Rate		0.84%
Investment Maturity Date		Jul. 06, 2017
U.S. Treasury Bills, 0.890% due July 27, 2017 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[1]	43.81%
Value	[1]	$ 8,995,113
Principal Value	[1]	$ 9,000,000
Investment Interest Rate	[1]	0.89%
Investment Maturity Date	[1]	Jul. 27, 2017
Restricted for maintenance margin	[1]	$ 7,995,200
U.S. Treasury Bills, 0.905% due August 17, 2017 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity		38.92%
Value		$ 7,991,016
Principal Value		$ 8,000,000
Investment Interest Rate		0.905%
Investment Maturity Date		Aug. 17, 2017
U.S. Treasury Bills, 0.960% due August 31, 2017 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity		4.87%
Value		$ 998,496
Principal Value		$ 1,000,000
Investment Interest Rate		0.96%
Investment Maturity Date		Aug. 31, 2017
United States Treasury Obligations [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity		92.47%	[2]	95.62%	[3]
Value		$ 18,984,562	[2]	$ 23,853,157	[3]
Investments, cost		$ 18,984,221	[2]	$ 23,852,335	[3]
Money Market Mutual Fund [Member] | Affiliated Investments - Premier U.S. Government Money Portfolio - Institutional Class [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[4]	7.75%
Affiliated Investments, at Value	[4]	$ 1,591,026
Shares	[4]	1,591,026
Investment Interest Rate	[4]	0.86%
Investments, cost	[4]	$ 1,591,026
U.S. Treasury Bills, 0.475% due February 2, 2017 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity				12.02%
Value				$ 2,998,959
Principal Value				$ 3,000,000
Investment Interest Rate				0.475%
Investment Maturity Date				Feb. 02, 2017
U.S. Treasury Bills, 0.535% due May 11, 2017 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity				32.00%
Value				$ 7,983,184
Principal Value				$ 8,000,000
Investment Interest Rate				0.535%
Investment Maturity Date				May 11, 2017
Restricted for maintenance margin				$ 7,983,184
U.S. Treasury Bills, 0.625% due May 18, 2017 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity				51.60%
Value				$ 12,871,014
Principal Value				$ 12,900,000
Investment Interest Rate				0.625%
Investment Maturity Date				May 18, 2017

[1] United States Treasury Obligations of $7,995,200 are on deposit with the Commodity Broker and held as maintenance margin for open futures contracts.

[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] 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 year 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, 2017.