Derivative Instruments (Schedule Of Trading Gains (Losses) Of Futures And Forward Currency Contracts) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Derivative [Line Items]
Trading gains (losses) of futures and forward currency contracts	$ 4,830,147	$ 1,738,339	$ (17,648,027)	$ 4,695,439
Futures Contracts [Member]
Derivative [Line Items]
Trading gains (losses) of futures and forward currency contracts	2,789,408	1,350,508	(21,268,571)	6,308,452
Energies [Member]
Derivative [Line Items]
Trading gains (losses) of futures and forward currency contracts	593,366	(2,659,402)	5,582,670	(6,999,886)
Grains [Member]
Derivative [Line Items]
Trading gains (losses) of futures and forward currency contracts	(435,375)	642,858	384,196	1,967,023
Interest Rates [Member]
Derivative [Line Items]
Trading gains (losses) of futures and forward currency contracts	(1,813,422)	460,188	(2,448,170)	8,240,958
Livestock [Member]
Derivative [Line Items]
Trading gains (losses) of futures and forward currency contracts	56,980	(165,430)	322,100	44,980
Metals [Member]
Derivative [Line Items]
Trading gains (losses) of futures and forward currency contracts	548,309	(237,875)	121,408	(711,590)
Softs [Member]
Derivative [Line Items]
Trading gains (losses) of futures and forward currency contracts	(3,277)	285,979	(258,749)	206,226
Stock Indices [Member]
Derivative [Line Items]
Trading gains (losses) of futures and forward currency contracts	3,842,827	3,024,190	(24,972,026)	3,560,741
Forward Currency Contracts [Member]
Derivative [Line Items]
Trading gains (losses) of futures and forward currency contracts	$ 2,040,739	$ 387,831	$ 3,620,544	$ (1,613,013)