Derivative Instruments - Fair Value of Derivative Instruments (Details) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Fair Values of Derivative Instruments
Asset Derivatives	$ 4,509,174	$ 5,623,607
Liability Derivatives	$ (1,754,962)	$ (2,004,385)
Agriculturals | Deutsche Bank Total Return Swap Terminating April 30, 2019
Fair Values of Derivative Instruments
Sector exposure index	2.00%	4.00%
Energy | Deutsche Bank Total Return Swap Terminating April 30, 2019
Fair Values of Derivative Instruments
Sector exposure index	1.00%	2.00%
Interest rates | Deutsche Bank Total Return Swap Terminating April 30, 2019
Fair Values of Derivative Instruments
Sector exposure index	74.00%	58.00%
Interest rates | Deutsche Bank Total Return Swap Terminating July 1, 2020
Fair Values of Derivative Instruments
Sector exposure index	46.00%	52.00%
Metals | Deutsche Bank Total Return Swap Terminating April 30, 2019
Fair Values of Derivative Instruments
Sector exposure index	2.00%	1.00%
Stock indices | Deutsche Bank Total Return Swap Terminating April 30, 2019
Fair Values of Derivative Instruments
Sector exposure index	4.00%	4.00%
Stock indices | Deutsche Bank Total Return Swap Terminating July 1, 2020
Fair Values of Derivative Instruments
Sector exposure index	22.00%	15.00%
Futures Contracts
Fair Values of Derivative Instruments
Asset Derivatives	$ 1,548,807	$ 2,952,613
Liability Derivatives	(1,584,619)	(1,225,072)
Fair Value	(35,812)	1,727,541
Futures Contracts | Agriculturals
Fair Values of Derivative Instruments
Asset Derivatives	90,053	137,471
Liability Derivatives	(116,177)	(21,434)
Fair Value	(26,124)	116,037
Futures Contracts | Currencies
Fair Values of Derivative Instruments
Asset Derivatives	316,799	319,952
Liability Derivatives	(38,718)	(279,232)
Fair Value	278,081	40,720
Futures Contracts | Energy
Fair Values of Derivative Instruments
Asset Derivatives	151,132	213,143
Liability Derivatives	(279,118)	(29,596)
Fair Value	(127,986)	183,547
Futures Contracts | Interest rates
Fair Values of Derivative Instruments
Asset Derivatives	262,011	1,472,305
Liability Derivatives	(482,520)	(230,289)
Fair Value	(220,509)	1,242,016
Futures Contracts | Meats
Fair Values of Derivative Instruments
Asset Derivatives	760	34,138
Liability Derivatives	(18,778)	(20,908)
Fair Value	(18,018)	13,230
Futures Contracts | Metals
Fair Values of Derivative Instruments
Asset Derivatives	488,821	489,925
Liability Derivatives	(429,896)	(224,143)
Fair Value	58,925	265,782
Futures Contracts | Soft commodities
Fair Values of Derivative Instruments
Asset Derivatives	15,631	149,703
Liability Derivatives	(72,951)	(25,803)
Fair Value	(57,320)	123,900
Futures Contracts | Stock indices
Fair Values of Derivative Instruments
Asset Derivatives	223,600	135,976
Liability Derivatives	(146,461)	(393,667)
Fair Value	77,139	(257,691)
Forward Contracts
Fair Values of Derivative Instruments
Fair Value	96,101	(41,428)
Forward Contracts | Currencies
Fair Values of Derivative Instruments
Asset Derivatives	183,679	142,015
Liability Derivatives	(87,578)	(183,443)
Fair Value	$ 96,101	$ (41,428)
Forward Contracts | Currencies | Deutsche Bank Total Return Swap Terminating April 30, 2019
Fair Values of Derivative Instruments
Sector exposure index	17.00%	31.00%
Forward Contracts | Currencies | Deutsche Bank Total Return Swap Terminating July 1, 2020
Fair Values of Derivative Instruments
Sector exposure index	32.00%	33.00%
Swap Contracts
Fair Values of Derivative Instruments
Asset Derivatives	$ 2,776,688	$ 2,528,979
Liability Derivatives	(82,765)	(595,870)
Fair Value	$ 2,693,923	$ 1,933,109
Swap Contracts | Deutsche Bank Total Return Swap Terminating April 30, 2019
Fair Values of Derivative Instruments
Sector exposure index	100.00%	100.00%
Swap Contracts | Deutsche Bank Total Return Swap Terminating July 1, 2020
Fair Values of Derivative Instruments
Sector exposure index	100.00%	100.00%