Schedule of Investments (Unaudited) - Futures Contracts - Futures [Member]		3 Months Ended	12 Months Ended
		Mar. 31, 2017 USD ($) Contract	Dec. 31, 2016 USD ($) Contract
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity		(1.43%)	0.24%
Unrealized Appreciation/ (Depreciation)	[1]	$ (10,539,511)	$ 1,988,810
Notional Value		$ 736,000,992	$ 845,905,220
United States of America, Dollars | ICE FUTURES U.S. [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders' Equity		(1.43%)	0.24%
Unrealized Appreciation/ (Depreciation)	[1]	$ (10,539,511)	$ 1,988,810
Notional Value		$ 736,000,992	$ 845,905,220
Number of Contracts | Contract		7,344	8,270
Maturity Date		Jun. 19, 2019	Mar. 13, 2017

[1] Unrealized appreciation/(depreciation) is presented above, net by contract.