Trading Activities - Trading Gains and Losses, by Market Sector, on Derivative Instruments (Detail)	12 Months Ended
	Dec. 31, 2018 USD ($)
Derivative [Line Items]
Trading gains and losses	$ 6,125,445
Currencies [Member]
Derivative [Line Items]
Trading gains and losses	(361,231)
Energy [Member]
Derivative [Line Items]
Trading gains and losses	5,468,819
Grains [Member]
Derivative [Line Items]
Trading gains and losses	147,389
Interest Rates Non-U.S. [Member]
Derivative [Line Items]
Trading gains and losses	17,430
Livestock [Member]
Derivative [Line Items]
Trading gains and losses	570,324
Metals [Member]
Derivative [Line Items]
Trading gains and losses	(865,848)
Softs [Member]
Derivative [Line Items]
Trading gains and losses	$ 1,148,562