Derivative Instruments - Effect of Derivatives on Statement of Operations (Details)	12 Months Ended
	Dec. 31, 2019 USD ($) instrument	Dec. 31, 2018 USD ($) instrument	Dec. 31, 2017 USD ($) instrument
Derivative Instruments
Rarely exceeded margin-to-equity ratio (as a percent)	25.00%
Effect of Derivative Instruments on the Consolidated Statement of Operations
Gains (losses) on derivatives instruments	$ 7,548,576	$ (3,242,956)	$ 3,123,843
Futures, Forward, and Swap Contracts
Effect of Derivative Instruments on the Consolidated Statement of Operations
Gains (losses) on derivatives instruments	$ 7,548,576	$ (3,242,956)	$ 3,123,843
Futures Contracts
Derivative Instruments
Monthly average number of derivative instruments bought and sold | instrument	7,863	19,056	38,106
Effect of Derivative Instruments on the Consolidated Statement of Operations
Gains (losses) on derivatives instruments	$ 6,063,337	$ (4,076,399)	$ 3,581,772
Futures Contracts | Agriculturals
Effect of Derivative Instruments on the Consolidated Statement of Operations
Gains (losses) on derivatives instruments	(177,141)	(1,206,749)	(2,343,148)
Futures Contracts | Currencies
Effect of Derivative Instruments on the Consolidated Statement of Operations
Gains (losses) on derivatives instruments	(414,477)	(194,875)	(3,320,635)
Futures Contracts | Energy
Effect of Derivative Instruments on the Consolidated Statement of Operations
Gains (losses) on derivatives instruments	(728,265)	1,051,284	(4,612,712)
Futures Contracts | Interest rates
Effect of Derivative Instruments on the Consolidated Statement of Operations
Gains (losses) on derivatives instruments	5,434,332	882,364	(8,492,797)
Futures Contracts | Meats
Effect of Derivative Instruments on the Consolidated Statement of Operations
Gains (losses) on derivatives instruments	(97,912)	(376,875)	266,929
Futures Contracts | Metals
Effect of Derivative Instruments on the Consolidated Statement of Operations
Gains (losses) on derivatives instruments	530,405	(707,249)	(1,954,292)
Futures Contracts | Soft commodities
Effect of Derivative Instruments on the Consolidated Statement of Operations
Gains (losses) on derivatives instruments	(204,249)	966,280	220,619
Futures Contracts | Stock indices
Effect of Derivative Instruments on the Consolidated Statement of Operations
Gains (losses) on derivatives instruments	$ 1,720,644	$ (4,490,579)	$ 23,817,809
Forward Contracts
Derivative Instruments
Monthly average number of derivative instruments bought and sold | instrument	271	448	585
Effect of Derivative Instruments on the Consolidated Statement of Operations
Gains (losses) on derivatives instruments	$ 380,909	$ 79,646	$ (2,371,939)
Forward Contracts | Currencies
Effect of Derivative Instruments on the Consolidated Statement of Operations
Gains (losses) on derivatives instruments	380,909	79,646	(2,371,940)
Swap Contracts
Effect of Derivative Instruments on the Consolidated Statement of Operations
Gains (losses) on derivatives instruments	$ 1,104,330	$ 753,797	$ 1,914,010