Schedule of Investments (Unaudited) - Futures Contracts		3 Months Ended	12 Months Ended
		Mar. 31, 2019 USD ($) Contract	Dec. 31, 2018 USD ($) Contract
Schedule of Investments [Line Items]
Commodity Futures Contracts, Value		$ 459,690,280	$ 499,957,015
Long | Futures [Member]
Schedule of Investments [Line Items]
Commodity Futures Contracts, Value	[1]	(19,081,777)	(17,860,885)
Commodity Futures Contracts, Unrealized Appreciation (Depreciation)	[1]	$ (19,081,777)	$ (17,860,885)
Long | Futures [Member] | Corn [Member] | CBOT [Member]
Schedule of Investments [Line Items]
Commodity Futures Contracts, Number of Contracts | Contract		2,996	3,156
Commodity Futures Contracts, Expiration Date		Sep. 30, 2019	Sep. 30, 2019
Commodity Futures Contracts, Notional Value		$ 56,175,000	$ 62,094,300
Commodity Futures Contracts, Value	[1]	(4,824,723)	(2,228,968)
Commodity Futures Contracts, Unrealized Appreciation (Depreciation)	[1]	$ (4,824,723)	$ (2,228,968)
Long | Futures [Member] | Soybean [Member] | CBOT [Member]
Schedule of Investments [Line Items]
Commodity Futures Contracts, Number of Contracts | Contract		1,290	1,359
Commodity Futures Contracts, Expiration Date		Nov. 30, 2019	Nov. 30, 2019
Commodity Futures Contracts, Notional Value		$ 59,275,500	$ 63,550,237
Commodity Futures Contracts, Value	[1]	(845,176)	267,411
Commodity Futures Contracts, Unrealized Appreciation (Depreciation)	[1]	$ (845,176)	$ 267,411
Long | Futures [Member] | Wheat [Member] | CBOT [Member]
Schedule of Investments [Line Items]
Commodity Futures Contracts, Number of Contracts | Contract		1,113	1,172
Commodity Futures Contracts, Expiration Date		Jul. 31, 2019	Jul. 31, 2019
Commodity Futures Contracts, Notional Value		$ 25,793,775	$ 30,384,100
Commodity Futures Contracts, Value	[1]	(6,764,194)	(4,100,713)
Commodity Futures Contracts, Unrealized Appreciation (Depreciation)	[1]	$ (6,764,194)	$ (4,100,713)
Long | Futures [Member] | Wheat KCB [Member] | CBOT [Member]
Schedule of Investments [Line Items]
Commodity Futures Contracts, Number of Contracts | Contract		1,104	1,163
Commodity Futures Contracts, Expiration Date		Jul. 31, 2019	Jul. 31, 2019
Commodity Futures Contracts, Notional Value		$ 24,163,800	$ 29,801,875
Commodity Futures Contracts, Value	[1]	(9,054,066)	(5,459,111)
Commodity Futures Contracts, Unrealized Appreciation (Depreciation)	[1]	$ (9,054,066)	$ (5,459,111)
Long | Futures [Member] | Feeder Cattle [Member] | CME SWAPS MARKETS (CME) [Member]
Schedule of Investments [Line Items]
Commodity Futures Contracts, Number of Contracts | Contract		272	293
Commodity Futures Contracts, Expiration Date		May 31, 2019	Mar. 31, 2019
Commodity Futures Contracts, Notional Value		$ 20,233,400	$ 21,498,875
Commodity Futures Contracts, Value	[1]	247,650	644,019
Commodity Futures Contracts, Unrealized Appreciation (Depreciation)	[1]	$ 247,650	$ 644,019
Long | Futures [Member] | Lean Hogs [Member] | CME SWAPS MARKETS (CME) [Member]
Schedule of Investments [Line Items]
Commodity Futures Contracts, Number of Contracts | Contract		1,187	1,755
Commodity Futures Contracts, Expiration Date		Jun. 30, 2019	Feb. 28, 2019
Commodity Futures Contracts, Notional Value		$ 42,043,540	$ 42,804,450
Commodity Futures Contracts, Value	[1]	5,718,151	(640,916)
Commodity Futures Contracts, Unrealized Appreciation (Depreciation)	[1]	$ 5,718,151	$ (640,916)
Long | Futures [Member] | Live Cattle [Member] | CME SWAPS MARKETS (CME) [Member]
Schedule of Investments [Line Items]
Commodity Futures Contracts, Number of Contracts | Contract		1,327	1,320
Commodity Futures Contracts, Expiration Date		Jun. 30, 2019	Feb. 28, 2019
Commodity Futures Contracts, Notional Value		$ 63,165,200	$ 65,406,000
Commodity Futures Contracts, Value	[1]	(600,590)	1,922,027
Commodity Futures Contracts, Unrealized Appreciation (Depreciation)	[1]	$ (600,590)	$ 1,922,027
Long | Futures [Member] | Cocoa [Member] | ICE FUTURES U.S. [Member]
Schedule of Investments [Line Items]
Commodity Futures Contracts, Number of Contracts | Contract		2,295	2,454
Commodity Futures Contracts, Expiration Date		May 31, 2019	Mar. 31, 2019
Commodity Futures Contracts, Notional Value		$ 52,326,000	$ 59,288,640
Commodity Futures Contracts, Value	[1]	564,859	1,657,953
Commodity Futures Contracts, Unrealized Appreciation (Depreciation)	[1]	$ 564,859	$ 1,657,953
Long | Futures [Member] | Coffee [Member] | ICE FUTURES U.S. [Member]
Schedule of Investments [Line Items]
Commodity Futures Contracts, Number of Contracts | Contract		1,151	1,248
Commodity Futures Contracts, Expiration Date		May 31, 2019	Mar. 31, 2019
Commodity Futures Contracts, Notional Value		$ 40,788,563	$ 47,665,800
Commodity Futures Contracts, Value	[1]	(5,542,388)	(8,353,460)
Commodity Futures Contracts, Unrealized Appreciation (Depreciation)	[1]	$ (5,542,388)	$ (8,353,460)
Long | Futures [Member] | Cotton [Member] | ICE FUTURES U.S. [Member]
Schedule of Investments [Line Items]
Commodity Futures Contracts, Number of Contracts | Contract		326	350
Commodity Futures Contracts, Expiration Date		May 31, 2019	Mar. 31, 2019
Commodity Futures Contracts, Notional Value		$ 12,650,430	$ 12,635,000
Commodity Futures Contracts, Value	[1]	537,985	(1,369,269)
Commodity Futures Contracts, Unrealized Appreciation (Depreciation)	[1]	$ 537,985	$ (1,369,269)
Long | Futures [Member] | Sugar [Member] | ICE FUTURES U.S. [Member]
Schedule of Investments [Line Items]
Commodity Futures Contracts, Number of Contracts | Contract		4,019	4,238
Commodity Futures Contracts, Expiration Date		Sep. 30, 2019	Sep. 30, 2019
Commodity Futures Contracts, Notional Value		$ 58,291,576	$ 59,474,397
Commodity Futures Contracts, Value	[1]	1,480,715	(199,858)
Commodity Futures Contracts, Unrealized Appreciation (Depreciation)	[1]	$ 1,480,715	$ (199,858)

[1] Unrealized Appreciation (Depreciation) and Value are presented above, net by contract.