Trading Activities - Trading Gains and Losses, by Market Sector, on Derivative Instruments (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Derivative [Line Items]
Gain (loss) from trading	$ (582,123)	$ 1,026,391	$ (910,835)	$ 1,077
Commodity [Member]
Derivative [Line Items]
Gain (loss) from trading	(192,927)	915,609	(1,163,855)	(665,555)
Equity [Member]
Derivative [Line Items]
Gain (loss) from trading	259,761	(275,220)	(261,108)	111,624
Currencies [Member]
Derivative [Line Items]
Gain (loss) from trading	(320,888)	492,855	(455,185)	879,754
Interest Rates [Member]
Derivative [Line Items]
Gain (loss) from trading	$ (328,069)	$ (106,853)	$ 969,313	$ (324,746)