Trading Activities - Trading Gains and Losses, by Market Sector, on Derivative Instruments (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Derivative [Line Items]
Gain (loss) from trading	$ 212,293	$ 2,625,968
Commodity [Member]
Derivative [Line Items]
Gain (loss) from trading	(484,450)	110,109
Equity [Member]
Derivative [Line Items]
Gain (loss) from trading	(198,923)	761,162
Foreign Currency [Member]
Derivative [Line Items]
Gain (loss) from trading	277,766	803,465
Interest Rate [Member]
Derivative [Line Items]
Gain (loss) from trading	$ 617,900	$ 951,232