Schedule of Investments (Unaudited) - Treasury Bills and Money Market Fund - USD ($)		9 Months Ended		12 Months Ended
		Sep. 30, 2016		Dec. 31, 2015
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity		100.01%
Value		$ 700,927,362		$ 1,077,913,905
Affiliated investments, at value and cost		39,228,727
Total Investments (cost $740,074,177)		740,156,089		1,077,913,905
Investments, cost		$ 740,074,177		$ 1,077,885,299
U.S. Treasury Bills, 0.250% due October 6, 2016 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity		32.43%
Value		$ 239,998,320
Principal Value		$ 240,000,000
Investment Interest Rate		0.25%
Investment Maturity Date		Oct. 06, 2016
U.S. Treasury Bills, 0.180% due October 20, 2016 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity		20.27%
Value		$ 149,991,300
Principal Value		$ 150,000,000
Investment Interest Rate		0.18%
Investment Maturity Date		Oct. 20, 2016
U.S. Treasury Bills, 0.160% due October 27, 2016 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[1]	17.97%
Value	[1]	$ 132,983,774
Principal Value	[1]	$ 133,000,000
Investment Interest Rate	[1]	0.16%
Investment Maturity Date	[1]	Oct. 27, 2016
Restricted for maintenance margin	[1]	$ 15,998,027
U.S. Treasury Bills, 0.300% due November 17, 2016 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity		0.54%
Value		$ 3,999,208
Principal Value		$ 4,000,000
Investment Interest Rate		0.30%
Investment Maturity Date		Nov. 17, 2016
U.S. Treasury Bills, 0.335% due December 1, 2016 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity		23.50%
Value		$ 173,954,760
Principal Value		$ 174,000,000
Investment Interest Rate		0.335%
Investment Maturity Date		Dec. 01, 2016
United States Treasury Obligations [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity		94.71%	[2]	95.09%	[3]
Value		$ 700,927,362	[2]	$ 1,077,913,905	[3]
Investments, cost		$ 700,845,450	[2]	$ 1,077,885,299	[3]
Money Market Mutual Fund [Member] | Premier Portfolio- Institutional Class, 0.34% [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[4]	5.30%
Affiliated investments, at value and cost	[4]	$ 39,228,727
Shares	[4]	39,228,727
Investment Interest Rate	[4]	0.34%
Investments, cost	[4]	$ 39,228,727
U.S. Treasury Bills, 0.235% due January 7, 2016 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity				12.35%
Value				$ 139,999,440
Principal Value				$ 140,000,000
Investment Interest Rate				0.235%
Investment Maturity Date				Jan. 07, 2016
U.S. Treasury Bills, 0.205% due January 14, 2016 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity				17.64%
Value				$ 199,994,400
Principal Value				$ 200,000,000
Investment Interest Rate				0.205%
Investment Maturity Date				Jan. 14, 2016
U.S. Treasury Bills, 0.195% due January 21, 2016 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity	[5]			13.67%
Value	[5]			$ 154,993,645
Principal Value	[5]			$ 155,000,000
Investment Interest Rate	[5]			0.195%
Investment Maturity Date	[5]			Jan. 21, 2016
Restricted for maintenance margin	[5]			$ 34,998,099
U.S. Treasury Bills, 0.170% due January 28, 2016 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity				17.64%
Value				$ 199,983,600
Principal Value				$ 200,000,000
Investment Interest Rate				0.17%
Investment Maturity Date				Jan. 28, 2016
U.S. Treasury Bills, 0.200% due February 4, 2016 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity				2.03%
Value				$ 22,998,206
Principal Value				$ 23,000,000
Investment Interest Rate				0.20%
Investment Maturity Date				Feb. 04, 2016
U.S. Treasury Bills, 0.135% due February 11, 2016 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity				8.82%
Value				$ 99,986,800
Principal Value				$ 100,000,000
Investment Interest Rate				0.135%
Investment Maturity Date				Feb. 11, 2016
U.S. Treasury Bills, 0.145% due February 18, 2016 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity				9.35%
Value				$ 105,986,008
Principal Value				$ 106,000,000
Investment Interest Rate				0.145%
Investment Maturity Date				Feb. 18, 2016
U.S. Treasury Bills, 0.140% due February 25, 2016 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity				0.27%
Value				$ 2,999,706
Principal Value				$ 3,000,000
Investment Interest Rate				0.14%
Investment Maturity Date				Feb. 25, 2016
U.S. Treasury Bills, 0.215% due March 3, 2016 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity				5.73%
Value				$ 64,989,730
Principal Value				$ 65,000,000
Investment Interest Rate				0.215%
Investment Maturity Date				Mar. 03, 2016
U.S. Treasury Bills, 0.280% due March 10, 2016 [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity				7.59%
Value				$ 85,982,370
Principal Value				$ 86,000,000
Investment Interest Rate				0.28%
Investment Maturity Date				Mar. 10, 2016

[1] United States Treasury Obligations of $15,998,027 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 September 30, 2016.

[5] United States Treasury Obligations of $34,998,099 are on deposit with the Commodity Broker and held as maintenance margin for open futures contracts.