Derivative Instruments and Hedging Activities (Details) - Trading Gains (Losses) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Trading Activity, Gains and Losses, Net [Line Items]
Trading gain (loss)	$ (530,614)	$ (216,752)	$ (397,586)	$ (1,370,939)
Agriculture [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Trading gain (loss)	(399,350)	(116,326)	(184,663)	(316,348)
Currency [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Trading gain (loss)	(137,854)	(205,017)	(176,681)	(643,324)
Energy [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Trading gain (loss)	(133,992)	(15,791)	(13,094)	182,210
Indices [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Trading gain (loss)	(58,059)	(375,453)	(217,160)	(337,237)
Interest Rates [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Trading gain (loss)	(17,393)	425,208	(24,325)	137,614
Metal [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Trading gain (loss)	$ 216,034	$ 70,627	$ 218,337	$ (393,854)