Derivative Instruments and Hedging Activities (Trading Gains (Loss)) (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Trading Activity, Gains and Losses, Net [Line Items]
Trading gain (loss)	$ 133,028	$ (1,154,187)
Agriculture [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Trading gain (loss)	212,660	(200,022)
Currency [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Trading gain (loss)	(36,443)	(438,307)
Energy [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Trading gain (loss)	120,898	198,001
Indices [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Trading gain (loss)	(159,118)	38,216
Interest Rates [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Trading gain (loss)	(6,931)	(287,594)
Metals [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Trading gain (loss)	$ 1,962	$ (464,481)