Schedule of Investments - Futures Contracts - Futures [Member]		12 Months Ended
		Dec. 31, 2016 USD ($) Contract	Dec. 31, 2015 USD ($) Contract
Schedule of Investments [Line Items]
Percentage of Shareholders’ Equity		(3.33%)	(0.13%)
Unrealized Appreciation/ (Depreciation)	[1]	$ (24,100,168)	$ (857,179)
Notional Value		$ 723,253,064	$ 674,103,619
Corn [Member] | CME SWAPS MARKETS (CBOT) [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders’ Equity		0.13%	(0.68%)
Unrealized Appreciation/ (Depreciation)	[1]	$ 934,349	$ (4,598,933)
Notional Value		$ 89,304,188	$ 80,172,162
Number of Contracts | Contract		4,811	4,273
Maturity Date		Sep. 14, 2017	Sep. 14, 2016
Soybean [Member] | CME SWAPS MARKETS (CBOT) [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders’ Equity		0.32%	(0.17%)
Unrealized Appreciation/ (Depreciation)	[1]	$ 2,343,146	$ (1,150,721)
Notional Value		$ 91,851,862	$ 83,993,662
Number of Contracts | Contract		1,857	1,903
Maturity Date		Nov. 14, 2017	Nov. 14, 2016
Wheat [Member] | CME SWAPS MARKETS (CBOT) [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders’ Equity		(1.44%)	(0.59%)
Unrealized Appreciation/ (Depreciation)	[1]	$ (10,374,494)	$ (3,988,618)
Notional Value		$ 43,294,725	$ 39,336,550
Number of Contracts | Contract		1,994	1,628
Maturity Date		Jul. 14, 2017	Jul. 14, 2016
Wheat KCB [Member] | CME SWAPS MARKETS (CBOT) [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders’ Equity		(1.16%)	(1.24%)
Unrealized Appreciation/ (Depreciation)	[1]	$ (8,400,291)	$ (8,354,144)
Notional Value		$ 44,389,750	$ 39,808,688
Number of Contracts | Contract		2,012	1,629
Maturity Date		Jul. 14, 2017	Jul. 14, 2016
Cattle Feeder [Member] | CME SWAPS MARKETS (CME) [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders’ Equity		0.09%	0.20%
Unrealized Appreciation/ (Depreciation)	[1]	$ 625,968	$ 1,387,903
Notional Value		$ 33,088,950	$ 27,493,200
Number of Contracts | Contract		529	336
Maturity Date		Mar. 30, 2017	Mar. 24, 2016
Lean Hogs [Member] | CME SWAPS MARKETS (CME) [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders’ Equity		1.87%	0.28%
Unrealized Appreciation/ (Depreciation)	[1]	$ 13,494,886	$ 1,863,261
Notional Value		$ 74,749,500	$ 58,723,600
Number of Contracts | Contract		2,825	2,455
Maturity Date		Feb. 14, 2017	Feb. 12, 2016
Live Cattle [Member] | CME SWAPS MARKETS (CME) [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders’ Equity		1.39%	(0.04%)
Unrealized Appreciation/ (Depreciation)	[1]	$ 10,023,897	$ (256,953)
Notional Value		$ 103,005,980	$ 84,816,000
Number of Contracts | Contract		2,219	1,550
Maturity Date		Feb. 28, 2017	Feb. 29, 2016
Cocoa [Member] | ICE FUTURES U.S. [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders’ Equity		(1.73%)	(0.16%)
Unrealized Appreciation/ (Depreciation)	[1]	$ (12,524,796)	$ (1,082,753)
Notional Value		$ 70,774,540	$ 73,788,780
Number of Contracts | Contract		3,329	2,298
Maturity Date		Mar. 16, 2017	Mar. 15, 2016
Coffee [Member] | ICE FUTURES U.S. [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders’ Equity		(2.29%)	0.39%
Unrealized Appreciation/ (Depreciation)	[1]	$ (16,548,729)	$ 2,646,488
Notional Value		$ 65,732,606	$ 77,160,300
Number of Contracts | Contract		1,279	1,624
Maturity Date		Mar. 21, 2017	Mar. 18, 2016
Cotton [Member] | ICE FUTURES U.S. [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders’ Equity		0.06%	0.06%
Unrealized Appreciation/ (Depreciation)	[1]	$ 471,475	$ 378,459
Notional Value		$ 20,877,075	$ 18,825,800
Number of Contracts | Contract		591	595
Maturity Date		Mar. 09, 2017	Mar. 08, 2016
Sugar [Member] | ICE FUTURES U.S. [Member]
Schedule of Investments [Line Items]
Percentage of Shareholders’ Equity		(0.57%)	1.82%
Unrealized Appreciation/ (Depreciation)	[1]	$ (4,145,579)	$ 12,298,832
Notional Value		$ 86,183,888	$ 89,984,877
Number of Contracts | Contract		4,126	5,473
Maturity Date		Sep. 29, 2017	Sep. 30, 2016

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