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	$ (482,671)	$ 1,059,026	$ 1,397,283	$ 1,097,494
Commodity [Member]
Derivative [Line Items]
Gain (loss) from trading	(589,371)	1,414,721	(1,491,751)	564,087
Equity [Member]
Derivative [Line Items]
Gain (loss) from trading	289,975	(947,760)	(394,975)	(456,039)
Currencies [Member]
Derivative [Line Items]
Gain (loss) from trading	63,980	(604,389)	407,418	(437,466)
Interest Rates [Member]
Derivative [Line Items]
Gain (loss) from trading	$ (247,255)	$ 1,196,454	$ 2,876,591	$ 1,426,912